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TZID:Asia/Kolkata
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DTSTART:20240101T000000
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20241202T103000
DTEND;TZID=Asia/Kolkata:20241202T130000
DTSTAMP:20260418T154820
CREATED:20241128T095209Z
LAST-MODIFIED:20241202T054246Z
UID:10000036-1733135400-1733144400@aero.iisc.ac.in
SUMMARY:Ph.D. (Engg): Experimental Study of Isolator Shock Trains in Confined Co-Flowing Supersonic Streams
DESCRIPTION:Futuristic high Mach number flight systems using advanced air-breathing propulsion technologies typically have multiple flow paths with supersonic flows that merge before exiting the vehicle. The supersonic-supersonic co-flow configuration is a canonical model used to study the fundamental aerodynamics of these interactions. A pseudo-shock is a composite gas-dynamic feature produced in viscous-dominated internal flows due to shock-boundary layer interaction. It consists of a series of shocks (shock train) and a mixing region. The terms pseudo-shock and shock train are often used interchangeably. The isolator is a finite-length\, constant-area duct that contains the shock train across a wide range of operating conditions. Understanding and predicting the length\, adverse pressure handling capacity\, and instability of the shock train in the isolator is crucial for designing weight-critical aerospace systems. Most research on shock trains in isolators involves configurations without a co-flowing supersonic stream\, where the adverse pressure ratio is imposed mechanically. Fluidic throttling\, however\, establishes the isolator shock train in a supersonic-supersonic co-flow configuration\, which differs fundamentally from mechanical throttling\, which necessitates separate investigations. The limited literature on shock trains in supersonic-supersonic co-flow configurations shows the shock train in a narrow operating regime\, either in the overexpanded regime or with combustion in the mixed stream producing back pressure. These studies\, conducted in opaque tubular ducts\, relied on pressure measurements to infer shock train characteristics. Empirical relations of the shock train pressure distribution and length were not in consensus. This thesis aims to understand the shock train in a supersonic-supersonic co-flow configuration using an optically accessible test section that provides simultaneous time-resolved schlieren imaging and static pressure measurement. A wide range of operating conditions is achieved by converting an existing blowdown supersonic jet facility to a pressure-vacuum-driven system. A new modular supersonic-supersonic co-flow test section is established with independent control over Mach number\, isolator length\, and stagnation conditions of the separate streams\, offering a larger parameter space than previous studies. The flow topology and morphology of 158 shock train cases are studied experimentally\, leading to several key insights. Novel image analysis techniques and static pressure profile analysis enabled the extraction of the last shock in the shock train\, correctly identifying the number of shocks and separating the mixing region. The maximum number of shocks for the supersonic-supersonic co-flow configuration ranges from 6 to 8\, and the maximum length of the shock train in the pseudo-shock occupies an average of 6 to 6.5 times the isolator duct height. A major outcome is the revelation of a secondary shock at the isolator duct exit due to local entrainment effects of the supersonic co-flow. This secondary shock can significantly contribute to about 20% to 25% of the overall adverse pressure ratio of the isolator. Consequently\, the addition of the secondary shock increases the overall adverse pressure-handling capacity of the isolator to 85% to 90% of the normal shock pressure ratio corresponding to the isolator entrance Mach number. Four transition points are identified based on significant changes in shock train topology. Across various operating conditions and geometries\, the normalized adverse pressure ratio (normalized with respect to the normal shock pressure ratio for the isolator entrance Mach number) ranges between 0.4 and 0.85. The flow topology in cases where the core flow is overexpanded is notably different due to the absence of the secondary shock in the shock train and the core flow’s contribution to the overall adverse pressure ratio. A comparative study between fluidic and mechanical throttling is conducted by implementing a mechanical flap module in the same setup. In the mechanically throttled case\, the shock train system has a lower adverse pressure ratio than the fluidically throttled case and a higher number of shocks\, with a maximum of about 10 to 11. The large dataset produced in this study allows a critical evaluation of well-known empirical correlations for shock trains\, leading to a new prediction algorithm to address gaps in their predictive ability. A regression-based correlation is developed to estimate the imposed adverse pressure ratio for the given Mach number and stagnation pressure combinations of both flows. An adaptive pressure increase factor for estimating the shock train leading edge is obtained using a linear regression model for cases with available wall static pressure data. The ratio of the imposed adverse pressure ratio to the incipient pressure ratio for a turbulent boundary layer is used to estimate the initiation of large amplitude oscillations of the shock train leading edge\, with an average factor of 2. Spectral analysis of the STLE oscillations using wall static pressure fluctuations and data-driven analysis of schlieren image datasets showed a broad-band spectrum without distinguishable tones\, with a spread of less than 200 Hz. \n  \nSpeaker: A Balaji Himakar \nResearch Supervisor: Srisha Rao M V
URL:https://aero.iisc.ac.in/event/ph-d-engg-experimental-study-of-isolator-shock-trains-in-confined-co-flowing-supersonic-streams/
LOCATION:STC Seminar Hall\, Dept. of Aerospace Engineering
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2024/11/Balaji-.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20241203T110000
DTEND;TZID=Asia/Kolkata:20241203T130000
DTSTAMP:20260418T154820
CREATED:20241126T095210Z
LAST-MODIFIED:20241129T054751Z
UID:10000033-1733223600-1733230800@aero.iisc.ac.in
SUMMARY:Ph.D. (Engg): Aeroacoustic sources in twin turbulent jets
DESCRIPTION:An understanding of the aeroacoustics of twin turbulent jets is essential for applications involving noise reduction in dual engine aircrafts and launch vehicles. The aeroacoustic dynamics of these jets are influenced by the spacing between the shear layer of the two jets as well as the spatio-temporal nature of the structures arising from the interaction between the two jets. In the present work\, we construct reduced-order models of aeroacoustic sources for single and twin subsonic jets ($M_j=0.9$\, $Re=3600$)\, with the individual jets being replicas of a single jet\, with the goal of accurately recovering the far-field sound over a rather wide band of frequencies St=[0.07\,1.0] and directivity angles\, phi = [30 deg\,120 deg] within a subdecibel level accuracy. These models are designed as linear combinations of spatio-temporally coherent SPOD modes obtained in terms of the Lighthill’s stress tensor\, which in turn is computed through large-eddy simulations (LES) of the turbulent jets.  The present investigation involves two sets of twin subsonic jets of diameter D each\, with spacings of 0.1D and 1D\, where the jets merge upstream and downstream of breakdown\, respectively.  This is observed to alter the dynamics of twin jet evolution.  The closely spaced twin jet decays the slowest due to reduced turbulent stresses which are\, however\, more broadband due to early merging.  Such jets also show strong shielding in the plane of jets\, especially at shallow directivity angles where sound levels may drop below that of the single jet.  The farther spaced twin jets have dynamics that are more akin to the constituent single jet with turbulent fluctuations peaking here at St=0.34\, but showing very little shielding\, with their OASPL mostly linked to the nature of extra flow structures created during merging.  Three-dimensional\, energy-ranked\, coherent structures (SPOD modes) for twin jets exhibit rather poor low-rank behaviour\, especially\, at the far-field spectral peak St=0.14\, unlike that of the single jet\, which is indicative of spatio-temporally complicated structures arising from the merging of the turbulent merging of the twin jets.  At St > 0.3\, the SPOD wavepackets show strong visual coherence\, resembling Kelvin–Helmholtz instability modes upstream of breakdown\, while at the lower frequencies there is very little spatial coherence with wavepackets peaking downstream of breakdown.  Although the leading SPOD modes radiate poorly\, reduced-order models using a subset of them\, up to 45 SPOD modes per frequency\, show for the first time remarkable match (within 1 dB) against the LES-predicted sound over 0.1 < St < 0.5\, at all angles investigated\, including that for the peak sound. At other frequencies\, the error barely exceeds a decibel\, except for the closely spaced twin jet which due to its greater hierarchy of spatio-temporal structures\, show slower convergence at the shallower angles for St > 0.5. \n  \nSpeaker:  Nishanth Muthichur \nResearch Supervisor: Santosh Hemchandra
URL:https://aero.iisc.ac.in/event/ph-d-engg-aeroacoustic-sources-in-twin-turbulent-jets/
LOCATION:Online
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2024/11/nishant.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20241205T103000
DTEND;TZID=Asia/Kolkata:20241205T123000
DTSTAMP:20260418T154820
CREATED:20241129T112328Z
LAST-MODIFIED:20241129T112328Z
UID:10000037-1733394600-1733401800@aero.iisc.ac.in
SUMMARY:Ph.D. (Engg): Development of Scalable UAV Swarm-based Cooperative Search and Mitigation Approaches for Wildfire Management
DESCRIPTION:Climate change has significantly exacerbated the wildfire seasons\, increasing their frequency\, duration\, and scale of destruction. Globally\, wildfires destroy approximately 400 million hectares of land annually\, resulting in significant biodiversity loss\, degradation of soil nutrients\, and other ecological consequences. The fire locations are often inaccessible for ground-based interventions due to the challenging terrain\, and current human-centered firefighting strategies are both dangerous and unreliable\, primarily due to limited situational awareness of evolving wildfire scenarios. Additionally\, wildfire scenarios frequently involve rapidly spreading clusters of fires that surpass available resources. The wildfire scenarios also have large fires that require simultaneous action from multiple resources for mitigation. Unmanned Aerial Vehicles (UAVs) have emerged as an effective solution for enhancing situational awareness and facilitating interventions during wildfires. This thesis develops UAV swarm-based strategies for wildfire detection\, monitoring\, and mitigation in resource-constrained and dynamic environments.\nThe thesis first focuses on the early mitigation of clustered fires by assigning and scheduling firefighting UAVs under resource limitations. The objective is to reduce biodiversity loss through early mitigation of fires as Single UAV Tasks (SUTs) before they escalate into complex multi-UAV coordination tasks. The problem is reformulated as a shortest-schedule-route optimization and solved using two centralized approaches: Genetic Algorithm-based Routing and Scheduling with Time Constraints (GARST) and Hybrid Particle Swarm Optimization-based Routing and Scheduling with Time Constraints (HPSO-RST). GARST and HPSO-RST evaluated on homogeneous and heterogeneous UAV teams under full observability conditions show that HPSO-RST outperforms GARST\, with a higher success rate\, reduced mean fitness values\, and minimized burned areas. However\, the centralized nature of GARST and HPSO-RST limits scalability and convergence in dynamic environments with continuously evolving task demands. These challenges are further compounded in real-world firefighting scenarios by partial observability\, limited UAV sensor capabilities\, and physical constraints of UAVs related to payload and endurance. \nNext\, the complexities of non-stationary wildfire scenarios\, including growing fires\, emerging new fires\, partial observability\, and heterogeneous temporal and physical constraints\, are addressed in the SUT mitigation. The problem is reformulated into a sequential spatiotemporal task assignment framework with non-stationary cost functions under partial observability. The Conflict-aware Resource-Efficient Decentralized Sequential planner (CREDS) is developed to address the challenges for early wildfire suppression using heterogeneous UAV teams. CREDS employs a three-phase approach: fire detection using a search algorithm\, local trajectory generation with an auction-based Resource-Efficient Decentralized Sequential planner (REDS) incorporating a novel Deadline-Prioritized Mitigation Cost (DPMC) function\, and a conflict-aware consensus algorithm to establish global trajectories for mitigation. CREDS achieves high success rates under various conditions\, handling diverse fire-to-UAV ratios with scalability and robustness. The CREDS is robust against physical constraints\, managing resource limitations through increased UAV capacity\, additional UAVs\, and efficient refueling strategies. In resource-constrained wildfire scenarios\, the evolving nature of the wildfire may result in multiple spatially distributed larger fires\, which require simultaneous and coordinated mitigation efforts from multiple UAVs. The single swarm mission with a decentralized approach has less likelihood of multiple UAVs detecting the same target. The multi-swarm missions with distributed solutions lead to the collective action of swarm members in the search and mitigation of larger fires in large unknown areas. \nFinally\, the thesis develops the Multi-Swarm Cooperative Information-Driven Search and Divide-and-Conquer Mitigation Control (MSCIDC) approach for large-scale wildfire scenarios. This methodology employs cooperative UAV swarms to enhance fire detection and mitigation efficiency. A two-stage search process combines exploration and exploitation\, guided by thermal sensor data\, for rapid identification of fire locations. Dynamic swarm behaviors\, including regulative repulsion and merging\, minimize detection and mitigation times\, while local attraction accelerates the response of non-detector UAVs. The divide-and-conquer strategy ensures effective\, non-overlapping sector allocation for fire mitigation. The simulations for a pine forest environment show that MSCIDC reduces the average burned area and mission time considerably compared to existing multi-UAV methods\, providing faster and more efficient wildfire management. \nOverall\, the thesis presents scalable UAV swarm-based solutions to address clustered and large-scale wildfire management challenges. The UAV swarm-based solutions integrate decentralized spatiotemporal task assignment and multi-swarm strategies to effectively minimize ecological damage and provide robust solutions for real-world disaster management applications. \nSpeaker: Josy John \nResearch Supervisor: Dr. Suresh Sundaram
URL:https://aero.iisc.ac.in/event/ph-d-engg-development-of-scalable-uav-swarm-based-cooperative-search-and-mitigation-approaches-for-wildfire-management/
LOCATION:STC Seminar Hall\, Dept. of Aerospace Engineering
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2024/11/john.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20241205T110000
DTEND;TZID=Asia/Kolkata:20241205T130000
DTSTAMP:20260418T154820
CREATED:20241204T104533Z
LAST-MODIFIED:20241204T104533Z
UID:10000040-1733396400-1733403600@aero.iisc.ac.in
SUMMARY:Ph.D. (Engg): Control of Alternating Flow Phenomena in Transonic Shock Wave Boundary Layer Interactions Over Payload Region of a Generic Launch Vehicle Model
DESCRIPTION:The transonic Mach number regime is a critical phase in the atmospheric ascent of launch vehicles\, where aerodynamic loads peak due to the combined effects of high freestream dynamic pressure and angle of attack. Besides high steady loads\, launch vehicles experience very high levels of pressure fluctuations caused by interactions between the unsteady λ-shock system and the boundary layer – a phenomenon known as Shock Wave Boundary Layer Interaction (SWBLI). These interactions can induce buffet excitation over the payload region\, leading to structural failure as well as control issues. NASA recommends limiting the nose cone semi-angle to 15° to mitigate shock oscillations\, labelling such designs as “Buffet-Proof.” However\, practical constraints such as payload mass & volume\, rocket diameter\, launch-pad limitations\, etc. necessitate the use of larger nose cone angles which are buffet-prone. While SWBLI has been well understood for two-dimensional flows\, data for three-dimensional launch vehicle type configurations is sparse in the literature\, with regard to even the basic understanding of the phenomena. Hence\, there is a need to develop physics-based models to handle SWBLI in practical cases. \nWind tunnel experiments were conducted to evaluate the aerodynamic impact of increasing nose cone angles to 20° and 25° in the transonic Mach number range. These investigations revealed critical flow characteristics such as abrupt jumps in pitching moments at small angles of attack (±4°)\, very high levels of pressure fluctuations\, λ-shock system oscillations\, and the occurrence of destabilizing counter-rotating vortices\, intermittent supersonic and subsonic flows (termed alternating flow phenomena) at specific Mach numbers of 0.90 and 0.94. The present research explores two approaches towards controlling SWBLI. The first involves a passive device\, a front-mounted Aerodisc\, systematically evaluated for the effect of geometric parameters at critical Mach numbers of 0.9 and 0.94 in the range of angles of attack of ±4°. The optimized Aerodisc configuration achieved the maximum noise reduction of 22 dB (Overall Sound Pressure Level\, OASPL). The second approach involves an active flow control technique using a pneumatic counter-flow jet. The jet parameters were varied during the tests. Jets with exit diameters of 3 mm and 4 mm operating at a pressure ratio of 3.2 achieved the greatest suppression by nearly 20 dB. Both the passive and active techniques demonstrated that by energizing the boundary layer\, the oscillating shock waves were stabilized\, the counter-rotating vortices removed and the upstream travelling Kutta-Waves associated with the alternating flows completely suppressed. \nThis research clearly brings out the basic physics of SWBLI and its control for 3-dimensional launch vehicle type configurations at transonic Mach numbers\, highlighting that the energizing the boundary layer is the key to control the transonic flow over launch vehicles with large blunt nose-cones. Based on the understanding of the physics of the phenomena and control accomplished in the present research\, it is possible to design and develop digital-twin based systems for efficient control of the phenomena and thereby improve the payload capability of heavy lift launch vehicles. \n  \nSpeaker: Dheerendra Bahadur Singh \nResearch Supervisor: Gopalan jagadeesh
URL:https://aero.iisc.ac.in/event/ph-d-engg-control-of-alternating-flow-phenomena-in-transonic-shock-wave-boundary-layer-interactions-over-payload-region-of-a-generic-launch-vehicle-model/
LOCATION:Centre of Excellence in Hypersonics conference hall\, Room No.AE-239\,
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2024/12/Dheerendra-.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20241206T140000
DTEND;TZID=Asia/Kolkata:20241206T170000
DTSTAMP:20260418T154820
CREATED:20241204T101223Z
LAST-MODIFIED:20241204T101223Z
UID:10000039-1733493600-1733504400@aero.iisc.ac.in
SUMMARY:Ph.D. (Engg): Multiscale modelling and design of multifunctional composites for microwave absorption applications
DESCRIPTION:Microwave absorption materials (MAMs) are crucial for both long-standing aeronautical and emerging space security applications\, with carbon-based materials traditionally dominating the field due to their exceptional strength and lightweight nature. In recent years\, other ceramic-based materials have emerged as promising alternatives\, due to their superior resistance to thermal detection\, due in turn to their low thermal conductivity and inertness to oxidation at high temperatures. However\, such ceramics by themselves often lack the mechanical flexibility and lightweight characteristics essential for aircraft. Combining such ceramics with carbon-based materials renders the achievement of an optimal balance of electromagnetic and mechanical (specific strength\, stiffness\, stability) performances\, possible. Traditional experimental approaches to designing MAMs are resource-intensive\, given the multidimensional parametric space that must be explored. This research adopts a multiscale computational framework\, leveraging minimal self-generated experimental data to efficiently design ceramic-carbon hybrid materials for broadband microwave absorption\, ensuring durability and low observability in extreme environments.\nThe initial phase investigates the microwave absorption capabilities of ceramic-based auxetic metamaterials with four distinct topologies: star\, re-entrant\, anti-tetrachiral\, and cross-chiral. These structures were chosen to analyse their reflection loss (RL) performance under transverse electric (TE) and transverse magnetic (TM) polarised electromagnetic (EM) waves. An in-house computationally-efficient homogenisation tool\, based on the Variational Asymptotic Method (VAM)\, was employed to derive the effective EM properties. These properties were then used to compute RL spectra by evaluating the scattering matrices. Interestingly\, the star and cross-chiral auxetic structures demonstrated identical absorption capabilities despite their architectural differences\, achieving a maximum absorption of 99.99% (RL of -40 dB) with a thickness of 3.5 mm under TM-polarised EM waves. These absorbers maintained RL < -10 dB for incidence angles up to 700. However\, TE-polarised EM waves led to more reflection (RL > -6 dB)\, highlighting a significant performance gap.\nLater\, to overcome the limitations observed with auxetic metamaterials\, a novel sandwich composite structure was proposed to achieve broadband RL under both TE and TM polarisations. This sandwich panel integrates ceramic-coated graphite fibre-reinforced polymer (C-GFRP) composite as the face sheet with a ceramic-based star auxetic metamaterial as the core. Representative volume elements (RVEs) of C-GFRP composites are generated using the in-house tool\, and the effective properties of the unidirectional C-GFRP face sheets were computed using the in-house homogenisation tool and validated with experimental results from the literature. A detailed parametric study of 300 analyses was conducted using the in-house transfer matrix method (TMM) tool to identify the optimal designs. Two configurations thus identified from the analysis are (a) Vf = 15% (uncoated) and (b) Vf = 20% with a ceramic coating volume fraction (Cf) of 70%. Configuration (a) achieved RL < -10 dB up to an incidence angle of 400\, while configuration (b) extended this performance up to 600. Both configurations attained broadband RL performance\, covering the entire X-band frequency range.\nThe final phase of the study experimentally validates the multiscale computational framework. For this purpose\, multiphase nanocomposites comprising carbon-based nanoparticles (MWCNTs) and other ceramic inclusions (BaTiO₃\, CoFe₂O₄) are fabricated and tested for broadband RL capabilities. Comprehensive characterisation techniques such as SEM\, TGA\, and X-ray computed tomography were employed to confirm nanoparticle morphology\, volume fractions\, and distribution. Reflection and transmission measurements using a two-port vector network analyser (VNA) provided scattering parameters within the X-band. Effective EM properties were derived using the Nicolson-Ross-Weir (NRW) algorithm. At the same time\, an in-house optimisation tool\, based on Nelder-Mead and L-BFGS-B methods\, was employed to extract the individual inclusion properties. Parametric studies revealed that composites with high BaTiO₃ or MWCNTs content exhibited surface impedance mismatches\, leading to EM wave reflection rather than absorption. In contrast\, CoFe₂O₄ dominant composites demonstrated superior broadband RL (< -10 dB) for different thickness samples\, attributed to improved surface impedance matching. Additionally\, the influence of incident angle and polarisation was assessed. TM-polarised EM waves provided broadband RL for incidence angles up to 800\, while TE-polarised EM waves were effective only up to 400 due to distinct field interaction mechanisms. The study demonstrates a versatile framework for designing novel nanocomposites tailored to broadband or frequency-selective microwave absorption applications\, addressing the limitations of traditional approaches.\n\nSpeaker: Attada Phanendra Kumar\nResearch Supervisor: Prof. Dineshkumar Harursampath
URL:https://aero.iisc.ac.in/event/ph-d-engg-multiscale-modelling-and-design-of-multifunctional-composites-for-microwave-absorption-applications/
LOCATION:STC Seminar Hall\, Dept. of Aerospace Engineering
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2024/12/Attada-.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20241209T103000
DTEND;TZID=Asia/Kolkata:20241209T123000
DTSTAMP:20260418T154820
CREATED:20241202T071527Z
LAST-MODIFIED:20241202T071527Z
UID:10000038-1733740200-1733747400@aero.iisc.ac.in
SUMMARY:Ph.D. (Engg): "Design and Development of Novel Quadcopters for Reliable Operations in Cluttered Environments"
DESCRIPTION:The quadcopters are increasingly used in cluttered environments as rapid advancements are made in the development of lightweight sensors and payloads. Intelligence Surveillance Reconnaissance (ISR) missions\,  crack detection on the interior surface of a pipe/tunnel\, and close inspection in tropical forest environments are a handful of examples where quadcopters are being deployed. Safe operation in these cluttered environments is challenging mainly due to the proximity of obstacles to the spinning propellers. The complete loss of the propeller makes it impossible to have full-attitude stability on traditional quadcopters. After the propeller failure\, the existing literature relies upon reduced-attitude control\, where the control authority about yaw is sacrificed. To maintain reduced attitude control\, the quadcopter must continuously spin rapidly about the yaw axis. Such a maneuver is risky\, and the quadcopter may not continue the mission after the actuator fails completely. \nFor reliable operation in a cluttered environment\, the quadcopter should also be able to reduce its span mid-flight to minimize the risk of the propeller collision with the obstacles. The quadcopter should remain fully controllable for all spans to enhance usability and applicability. The degree of span reduction should be controllable between the nominal and extreme states. Ideally\, the quadcopter should also be tolerant to the complete failure of the additional “span-reducing” actuator (not to be confused with primary rotor-based actuators). For the broader range of applications\, the concept or the mechanism of span-reducing should be weight-scalable.  The effective execution of an indoor cluttered environment mission may also require a mid-flight flipping quadcopter for gaining the perception of the environment along both nadir and zenith directions with respect to the payload.  Traditional quadcopters cannot sustain the inverted flight and thus lack the maneuverability and reliability to operate safely and effectively in a cluttered environment. Enhancements to the fundamental principles governing quadcopter dynamics are required to facilitate challenging operations in cluttered environments. \nThe first half of the presentation consists of the design and development of a morphing quadcopter called Scissorbot. Scissorbot is a novel mid-flight reconfigurable geometry quadcopter that reduces its lateral span using a single servo-motor coupled with a compact bevel differential gearbox. Scissorbot possesses unique practical features\, including weight-scalability\, geometrical symmetricity\, and fault tolerance to the servo-motor. Scissorbot achieves significant lateral-span reduction without the risk of propeller tip collision by positioning adjacent propellers in different planes. The maximum lateral-span reduction is 88% of its nominal value (highest reported in the literature). This work derives a detailed attitude dynamics model and analyzes the gearbox theoretically. Attitude control is accomplished by implementing a Sliding Mode Controller (SMC) that exhibits robustness to parametric uncertainties such as the moment of inertia and aerodynamic disturbances due to the overlapping of the propellers. The control allocation loop is parametrized with respect to the morphing angle to adapt to the reconfiguration process.  The performance of the Scissorbot is validated using simulations\, test-benches as well as real-world free-flight experiments. \nThe other half presents the design and development of a novel Variable-Pitch-Propeller (VPP) quadcopter called Heliquad. The cambered airfoil propeller-equipped Heliquad generates significantly more torque than its symmetrical airfoil counterpart\, ensuring full-attitude hover equilibrium on only three of its working actuators. VPPs can generate reverse thrust\, enabling mid-flight flip and sustained inverted flight on Heliquad. A unified control architecture ensures the tractability of the Heliquad. Furthermore\, a Neural-Network (NN) based control allocation method is proposed to address the non-linearities in the actuator dynamics. The control allocation is reconfigurable based on the index of the faulty actuator. For the experimental validation\, a prototype of  Heliquad is built. The design and analysis of the VPP mechanism installed on the Heliquad prototype are also presented. The performance of Heliquad is validated using simulations\, test-benches\, and real-world free-flight experiments. The safe recovery of a quadcopter architecture (Heliquad) with full attitude control after the complete failure of an actuator is demonstrated for the first time in the literature. \nSpeaker:  Kulkarni Eeshan Prashant \nResearch Supervisor: Prof Suresh Sundaram
URL:https://aero.iisc.ac.in/event/ph-d-engg-design-and-development-of-novel-quadcopters-for-reliable-operations-in-cluttered-environments/
LOCATION:STC Seminar Hall\, Dept. of Aerospace Engineering
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2024/12/Eeshan.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20241209T110000
DTEND;TZID=Asia/Kolkata:20241209T130000
DTSTAMP:20260418T154820
CREATED:20241209T043233Z
LAST-MODIFIED:20241209T052550Z
UID:10000042-1733742000-1733749200@aero.iisc.ac.in
SUMMARY:Boundary Layer Transition Experiment in a Supersonic Flight
DESCRIPTION:In fluid mechanics\, the boundary-layer transition is a very important phenomenon for high-speed flows because it severely affects the skin friction and heating rates on the model surface. The classical correlations for high-speed flows have been developed based on experimental observations in wind tunnels. When the experiments are performed\, they are mostly controlled by the flow Reynolds number because the maximum size of the model is fixed based on the size of the test section of a wind tunnel. In most cases\, artificial surface roughness is introduced to initiate a transition towards turbulence because of the restricted model size. The flow Reynolds number and Station number on the model surface are crucial non-dimensional indicative parameters that characterize the transition behaviour of the flow. A realistic approach to simulate the effect of model size for studying the boundary layer transition is to conduct a flight test. Against this backdrop\, a systematic procedure is adopted to design a generic ogive nose cone-cylinder payload module (0.7 m long) for a boundary-layer transition experiment in a supersonic flight. Nickel thin film gauges are used to infer heat transfer data on the payload module at various locations for 10s flight duration. The heat transfer data from the temperature history are obtained using two different techniques: one-dimensional semi-infinite heat conduction analysis and deconvolution method. The analysis from flight data indicates a peak Mach number of 2.018\, which is achieved after 1.157s of flight. The Reynolds number during the flight is of the order of 10 million \, which is an indication of completely turbulent flow during flight duration. It is also supported by heat transfer prediction through the Stanton number\, which falls in the range of 0.5 to 1.2. It is concluded that the length of the model is not sufficient to initiate a transition towards relaminarization because the Stanton number and Reynolds number variation do not show any drastic change at any of the gauge locations. However\, the promising surface temperature histories from nickel thin film gauges during flight are very useful to devise more realistic heat-transfer models for for higher time scales flow duration through inverse heat-conduction analysis and modern machine learning models.\n\n Speaker: Prof. Niranjan Sahoo\n\nBiography : \nProf. Sahoo’s research interests lie in high-speed aerodynamics\, ground test facilities\, measurements for forces and heat transfer\, shock waves\, and their applications in allied fields\, combustion\, energy \, hydrogen energy and storage. He has been awarded fellowships from DAAD Germany\, BOYCAST and Young Scientist Scheme from DSTHe has offered several online courses (Applied Thermodynamics\, Power Plant System Engineering\, Advanced Thermodynamics and Combustion\, Fundamentals of Compressible Flow) on NPTEL platform. He has over 115 Journal Publications\, 153 in conference proceedings and 11 Book Chapters.
URL:https://aero.iisc.ac.in/event/boundary-layer-transition-experiment-in-a-supersonic-flight/
LOCATION:AE Auditorium
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2024/12/Niranjan.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20241209T110000
DTEND;TZID=Asia/Kolkata:20241209T130000
DTSTAMP:20260418T154820
CREATED:20241209T045719Z
LAST-MODIFIED:20241209T051859Z
UID:10000043-1733742000-1733749200@aero.iisc.ac.in
SUMMARY:The Dual Mesh Control Domain Method: A Marriage of the Finite Element and Finite Volume Methods
DESCRIPTION:The finite element method (FEM) and finite volume method (FVM) are widely used numerical techniques for solving differential equations\, with FEM mainly applied in solid mechanics and FVM in heat transfer and fluid dynamics. Both methods have drawbacks: FEM can lead to discontinuities at element interfaces unless C1-continuous approximations are used\, while FVM relies on ad-hoc techniques from finite difference methods\, lacking explicit approximations and concepts of duality. In 2019\, Reddy introduced the dual mesh control domain method (DMCDM)\, combining features of both FEM and FVM. DMCDM uses a primal mesh for dependent variable interpolation and a dual mesh for integral satisfaction of governing equations\, enhancing the methods’ effectiveness. This lecture discusses DMCDM’s key features and demonstrates its applications in various linear and nonlinear problems. \nSpeaker: Prof J N Reddy \nBiography:  \nDr. Reddy is a Distinguished Professor and Regents’ Professor at Texas A&M University\, holding the O’Donnell Foundation Chair IV in Mechanical Engineering. An ISI highly cited researcher\, he has authored 25 textbooks and over 800 journal papers\, making significant contributions to applied mechanics\, particularly through his shear deformation theories\, including the Reddy third-order plate theory and Reddy layerwise theory. These theories have influenced commercial finite element software like ABAQUS and NISA. Recently\, his research has focused on locking-free shell finite elements and nonlocal continuum mechanics related to architected materials and structural failures. Dr. Reddy has received numerous prestigious awards\, including the 2023 Leonardo da Vinci Award\, the 2023 Michael Païdoussis Medal\, and the 2019 SP Timoshenko Medal\, among others. He is a member of eight national academies\, including the U.S. National\nAcademy of Engineering\, and a foreign fellow of several international engineering academies.
URL:https://aero.iisc.ac.in/event/the-dual-mesh-control-domain-method-a-marriage-of-the-finite-element-and-finite-volume-methods/
LOCATION:Auditorium\, Department of Physics\, IISc
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2024/12/reddy1.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20241218T110000
DTEND;TZID=Asia/Kolkata:20241218T123000
DTSTAMP:20260418T154820
CREATED:20241217T044151Z
LAST-MODIFIED:20241217T044151Z
UID:10000044-1734519600-1734525000@aero.iisc.ac.in
SUMMARY:Phase Transformations in Multifunctional Materials
DESCRIPTION:Phase transformation materials are characterized by their ability to rapidly and reversibly switch between distinct properties\, such as insulating and conducting\, paramagnetic and ferromagnetic\, or Li-rich and Li-poor. These transformations\, however\, are accompanied by abrupt structural changes in the crystal lattices\, which can nucleate defects\, accumulate strain energy\, and accelerate material decay. We investigate these transformations in multifunctional materials from the viewpoint of Ericksen’s multiple energy wells. By doing so\, we identify important links between material constants\, crystallographic microstructures\, and macroscopic properties. This approach to understanding material behavior from the perspective of energy landscapes may suggest new ways to design materials with improved properties and lifespans. In this talk\, I will present our findings on phase transformations in battery electrodes (intercalation compounds) and soft magnetic alloys.\n\n Speaker: Ananya Balakrishna\n\nBiography:\nAnanya Renuka Balakrishna is an Assistant Professor in the Materials Department at the University of California Santa Barbara. She received her B.Tech degree in Mechanical Engineering from the National Institute of Technology Karnataka and her Ph.D. in Solid Mechanics and Materials Engineering from the University of Oxford. Before her current appointment\, she was a Lindemann Postdoctoral Fellow at MIT and the University of Minnesota and joined the faculty in the Department of Aerospace & Mechanical Engineering at the University of Southern California in 2020. Her research group develops theoretical models to understand the interplay between fundamental material constants and microstructural instabilities\, and how they collectively shape the physical response of a material.
URL:https://aero.iisc.ac.in/event/phase-transformations-in-multifunctional-materials/
LOCATION:AE Auditorium
CATEGORIES:AE Seminar
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2024/12/Ananya-.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20241219T090000
DTEND;TZID=Asia/Kolkata:20241220T173000
DTSTAMP:20260418T154820
CREATED:20241219T044539Z
LAST-MODIFIED:20241219T044539Z
UID:10000045-1734598800-1734715800@aero.iisc.ac.in
SUMMARY:Two-Day Short Course on Mathematics and Computing of Risk\, Reliability and Resilience in Network and Enterprise Systems
DESCRIPTION:This course is designed to familiarize the students with the mathematical concepts and computational techniques in quantifying the risk\, reliability and resilience (RRR) of large\, complex systems\, in the presence of multiple types of uncertainty. Often the information available for RRR analysis is heterogeneous\, coming from multiple sources (models\, tests\, experts) and in multiple formats. The use of Bayesian methods to integrate heterogeneous information will be presented. The use of RRR quantification results in various types of decisions will be discussed\, such as system design\, manufacturing\, operations\, and sustainment. The concept and use of digital twins that continuously update the system model with incoming data to maintain high levels of system performance and resilience will be presented. Application examples from engineering systems (e.g.\, aircraft\, buildings)\, business enterprise systems (e.g.\, manufacturing and distribution supply chains)\, and civil infrastructure systems (e.g.\, power grid\, transportation) will be used to illustrate the RRR techniques for large complex systems. For more information\, please visit our website https://abcmc.iisc.ac.in/events/ \n  \nSpeaker: Dr. Sankaran Mahadevan \n  \nBiograpgy:  \nProfessor Sankaran Mahadevan has thirty-six years of research and teaching experience in reliability and risk methods\, uncertainty quantification\, model validation\, system health and risk management\, and optimization under uncertainty. His research has been extensively funded by NSF\, NASA\, FAA\, DOE\, DOD\, DOT\, NIST\, General Motors\, Chrysler\, Union Pacific\, American Railroad Association\, and Sandia\, Idaho\, Los Alamos and Oak Ridge national laboratories. His research contributions are documented in more than 700 publications\, including two textbooks on reliability methods and 350 journal papers. He is one of the world’s highest cited researchers in the field of uncertainty and risk analysis (Google Scholar h-index 90). He has directed 56 Ph.D. dissertations and 24 M. S. theses and has taught many industry and university short courses on the mathematics and computing of uncertainty and reliability analysis. Professor Mahadevan is a Fellow of AIAA\, Fellow of the Engineering Mechanics Institute (ASCE)\, and Fellow of Prognostics and Health Management Society (PHM). He is the winner of several prestigious awards including the Senior Distinguished Research Award from the International Association of Structural Safety and Reliability\, NASA Next Generation Design Tools award\, SAE Distinguished Probabilistic Methods Educator Award\, and best paper awards in several international conferences. He recently completed his service as President of the ASCE Engineering Mechanics Institute and Managing Editor of ASCE-ASME Journal of Risk and Uncertainty (Part B: Mechanical Engineering). He is currently Chair of the ASME VVUQ50 Committee on Advanced Manufacturing.
URL:https://aero.iisc.ac.in/event/two-day-short-course-on-mathematics-and-computing-of-risk-reliability-and-resilience-in-network-and-enterprise-systems/
LOCATION:Auditorium (AE 005)\, Department of Aerospace Engineering
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2024/12/TwoDay.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20241227T110000
DTEND;TZID=Asia/Kolkata:20241227T130000
DTSTAMP:20260418T154820
CREATED:20241224T090743Z
LAST-MODIFIED:20241224T090743Z
UID:10000046-1735297200-1735304400@aero.iisc.ac.in
SUMMARY:Ph.D. (Engg): Effect of Surface Roughness on Mechanical Strength of Adhesively Bonded CFRP Joints – Experimental and Numerical Studies
DESCRIPTION:This dissertation focuses on surface preparation and its effect on the shear strength of adhesively bonded Single Lap Joints (SLJs) in Carbon Fiber Reinforced Polymer (CFRP)\, their fracture properties\, and the associated Non-Destructive Evaluation (NDE) parameters. The surface preparation was carried out using different grades of emery paper so that the interfaces of different roughness were available for bonding. The morphology of the interfaces before bonding was captured with the light interferometry [Micro-System Analyzer (MSA)]. Then\, roughness parameters were characterized by contact-based measurements. The correlations of the contact angle between the droplet of liquid and the bonding interface with varied surface roughness and the increase in area with respect to the smoothest surface were established. CFRP\, one of the most preferred composite materials in the aerospace industry\, has been chosen in this study. \nA band of NDE techniques was utilized to evaluate the effects of surface roughness in ABJs of CFRP adherends. This included Ultrasonic Testing (UT)\, Infra-Red Thermography (IRT)\, Acoustic Wave Propagation (AWP)\, Acoustic Emission Testing (AET)\, X-ray Radiography Testing (XRT)\, and Digital Image Correlation (DIC). \nIn the FEA model it is difficult to model micro-roughness on the adherend of mesoscale. Hence\, an approach was presented to model the fracture in rough interfaces. Modelling of joints with varied roughness was considered\, and fracture properties were implemented in the commercial FEA software Abaqus. The surface-to-surface interactions were modelled for each interface. The interaction was based on the Cohesive Zone Model (CZM). Traction separation laws were derived from experimental fracture energies. \n  \nSpeaker: Laxmikant Mane Sarjerao \nResearch Supervisor: Prof Bhat M Ramachandra
URL:https://aero.iisc.ac.in/event/ph-d-engg-effect-of-surface-roughness-on-mechanical-strength-of-adhesively-bonded-cfrp-joints-experimental-and-numerical-studies/
LOCATION:STC Seminar Hall\, Dept. of Aerospace Engineering
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2024/12/Laxmikant-.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250110T150000
DTEND;TZID=Asia/Kolkata:20250110T170000
DTSTAMP:20260418T154820
CREATED:20241230T092927Z
LAST-MODIFIED:20241230T092927Z
UID:10000047-1736521200-1736528400@aero.iisc.ac.in
SUMMARY:PHONONIC MATERIALS – AN AVENUE FOR PASSIVE FLOW CONTROL
DESCRIPTION:Specific modal and non-modal mechanisms (flow coherences) in fluid flows\, associated with distinct time and length scales\, govern important flow phenomena\, e.g.\, laminar-to-turbulent transition\, turbulent drag\, and flow separation. Consequently\, numerous passive strategies featuring compliant materials have explored the effect of Fluid-structure interaction (FSI) on various flow coherences. In recent years\, the emergence of Phononic materials (PMs) with engineered internal architectures provides a powerful tool to encode desired material behavior. Therefore\, flow configurations leveraging fluid-PM interaction offer an exciting opportunity to precisely engineer the spatiotemporal scales of the structural response relative to the flow coherences\, allowing a more fundamental and systematic study of FSI physics. Initial research efforts adopting the fluid-PM framework have demonstrated effective interaction with flow instabilities\, e.g.\, Tollmien–Schlichting waves. Building on these efforts\, our research group explores interesting FSI dynamics of canonical fluid flow – PM configurations to illustrate the potential of PMs for passive flow control. \nIn this talk\, I will present an overview of the PM design strategy and numerical and experimental results from our current fluid-PM interaction research projects. We configure PMs as subsurfaces and explore their FSI with flow coherences in various flow settings\, e.g.\, flow coherences in a turbulent channel flow\, Karman vortex streets in a subsonic flow past a cylinder\, wake vortices in flow past an airfoil. \n  \nSpeaker: Dr. Vinod Ramakrishnan \n  \nBiography:  \nDr. Vinod Ramakrishnan is a Postdoctoral research associate working with Dr. Kathryn Matlack at the University of Illinois at Urbana-Champaign. His research involves numerical and experimental investigations of Fluid-Metamaterial interaction models to explore avenues for passive flow control. Vinod holds a PhD in Mechanical Engineering from the University of California San Diego (2023) and a B. Tech in Mechanical Engineering from IIT Gandhinagar (2018). He worked with Dr. Michael Frazier during his PhD\, where his research explored phase transitions and strategies to control domain walls in multistable metamaterials to promote their adoption in applications\, e.g.\, energy harvesting\, mechanical memory devices\, and deployable structures.
URL:https://aero.iisc.ac.in/event/phononic-materials-an-avenue-for-passive-flow-control/
LOCATION:AE Auditorium
CATEGORIES:AE Seminar
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2024/12/Vinod-.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250116T110000
DTEND;TZID=Asia/Kolkata:20250116T130000
DTSTAMP:20260418T154820
CREATED:20250115T054120Z
LAST-MODIFIED:20250115T054120Z
UID:10000048-1737025200-1737032400@aero.iisc.ac.in
SUMMARY:Ph.D. (Engg): Transonic shock buffet in an axial flow fan
DESCRIPTION:Transonic shock buffet\, a self-sustained shock oscillation resulting from shock-boundary layer interaction\, is observed across a range of operating points on the performance map of a transonic axial flow fan. Shock oscillations impart time-varying air loads on fan blades with the potential of leading to fatigue-induced structural failure. Accurate estimations of shock buffet onset\, shock displacement\, and buffet frequency are critical to lifing assessment of turbomachinery blades. This study focuses on predicting transonic shock buffet in a transonic axial flow fan using high-fidelity numerical simulations\, followed by investigation of its underlying mechanisms through wave propagation analysis and modal analysis of buffet flow. Steady flow solutions obtained using a RANS solver predict performance characteristics and capture key features of the fan’s shock structure in conformation with experimental and numerical results from the literature. Unsteady flow simulations on a full-annulus model using URANS successfully capture shock buffet and its salient attributes at two operating points—near design mass flow and near stall. Wave propagation analysis and spectral proper orthogonal decomposition of buffet flow reveal a feedback loop of upstream and downstream propagating pressure perturbation waves driving shock buffet. Subtle modification to Lee’s buffet model is proposed for accurately predicting buffet frequency in a turbomachinery context. Buffet flow is characterized by circumferential\, radial\, and stream-wise pressure perturbation waves\, with circumferential flow periodicity breaking down during buffet. A global stability analysis framework is presented and its prognostic potential for predicting shock buffet in turbomachinery is evaluated. The global stability analysis framework enables accurate prediction of buffet frequencies and associated modes with drastically reduced computational cost compared to that required for unsteady simulations. Finally\, the aeromechanical response of the fan to buffet-induced unsteady air loads is assessed. The buffet frequencies do not excite resonant blade vibrations or buffeting but induce an alternating mis-staggering structural response in the fan blades due to aerodynamic mistuning arising of buffet flow. In summary\, we have shown\, for the first time\, transonic shock buffet in an axial flow fan can be captured using a full-annulus simulation. Further\, this study advances the understanding of transonic shock buffet mechanisms\, demonstrating robust methodologies for predicting shock buffet\, and assessing its aeromechanical implications in turbomachinery. \n  \nSpeaker : Jyoti Ranjan Majhi \n  \nResearch Supervisor: Prof. Kartik Venkatraman.
URL:https://aero.iisc.ac.in/event/ph-d-engg-transonic-shock-buffet-in-an-axial-flow-fan/
LOCATION:Auditorium (AE 005)\, Department of Aerospace Engineering
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/01/Jyoti-.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250122T090000
DTEND;TZID=Asia/Kolkata:20250122T103000
DTSTAMP:20260418T154820
CREATED:20250122T033636Z
LAST-MODIFIED:20250122T050308Z
UID:10000049-1737536400-1737541800@aero.iisc.ac.in
SUMMARY:The 41st Annual Symposium on Space Science and Technology
DESCRIPTION:Indian Space Programme: has been a catalyst for advanced research\, technological innovation and space exploration in the country. Scientific data from ISRO’s earth observation\, lunar and planetary exploration missions are being used by hundreds of scientists across the country. More than 1000 R&D Projects have been supported through the RESPOND Programme and Space Technology cells. Human spaceflight programme is expected to provide an important platform for scientific research and development\, innovation and creativity. Microgravity science experiments in uncrewed and crewed missions will provide valuable insight into areas like crystal growth\, space agriculture\, cell and tissue growth and pharmaceutical research. It will also enable us to understand issues related to human health including muscular dystrophy\, heart disease and aging. The countermeasures developed could help in combating bone loss to help people dealing with osteoporosis A space-based platform such as the Bhartiya Antariksha Station has the potential to synergize national strengths and further enhance capabilities in sectors such as biotechnology\, robotics\, colloid research and combustion. Another objective of long duration microgravity research is to develop the ways and means to sustain human civilization away from earth. This has direct implication on human life on earth faced with depleting resources. The presentation on ‘Human spaceflight: A driver for Scientific research’ will briefly cover these aspects. \nSpeaker: Shri Imtiaz Ali Khan \n  \nBiography: \n1999-2014: Joined VSSC in 1999 and worked in processing and realization of Solid Rocket Motors. Contributed to development of new formulations\, propellant grains and processing techniques. This included PS0M-XL segments\, S-200 igniters\, ATV motors and Special Purpose Motors. Served as Manager\, Propellant Casting and Curing facility. Filed Patent for casting technique for thin webbed grains. Received ISRO Young Scientist award\, team achievement award and MR Kurup Gold medal. \n2014-2017: Served at Embassy of India\, Paris as Counsellor (Space). Contributed to enhancement of bilateral relations between India and France in Space. Participated in UNCOPUOS sessions at Vienna. Interacted with space agencies of Europe\, Germany and UK. \n2017–2021: Served as Officer on Special Duty at DoS Branch Secretariat\, New Delhi. Interacted with other Departments on Space applications\, satellite utilization and export control issues. Cabinet approvals for Human spaceflight programme\, GSLV MK III operationalization and PSLV flights were granted during the period. 2021-2022: Served as Group Director\, Biomedical Research\, Crew Administration and Training Group at HSFC. Astronaut Training Facility was established and commissioned. \n2022-2024: Director of the Directorate of Human Spaceflight Programme at ISRO HQ. Responsible for crew selection\, training\, national/international collaboration and programme management for Gaganyaan. \n 
URL:https://aero.iisc.ac.in/event/the-41st-annual-symposium-on-space-science-and-technology/
LOCATION:AE Auditorium
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/01/Imtiaz-.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250128T090000
DTEND;TZID=Asia/Kolkata:20250131T170000
DTSTAMP:20260418T154820
CREATED:20250127T042311Z
LAST-MODIFIED:20250127T042955Z
UID:10000050-1738054800-1738342800@aero.iisc.ac.in
SUMMARY:AERES 2025
DESCRIPTION:The Department of Aerospace Engineering\, IISc\, is excited to invite you to AERES 2025—a premier Aerospace Research Students’ Symposium. This 4-day event brings together MTech and PhD students from IISc and other leading institutes to showcase innovative research and connect with industry experts. \n  \nWhy Attend AERES 2025? \n• 6 Keynote Talks: Hear from distinguished leaders in the aerospace industry. \n• 2 Workshops: Enhance your skills with hands-on learning opportunities. \n• Oral and Poster Presentations: Discover groundbreaking research and engage in discussions on cutting-edge advancements. \nThis symposium offers an excellent platform to network\, learn from industry leaders\, and explore the latest trends in aerospace technology. \nThis year we are also welcoming select student participants from Indian Institute of Space Science and Technology (IIST) to attend and present their research in AERES. \n  \nSchedule Link:  \nhttps://ca00f07c-32a8-46fd-ad7a-fb170b00b80e.filesusr.com/ugd/0858f9_0ebf6e9519354c66ae41e406446cbd13.pdf
URL:https://aero.iisc.ac.in/event/aeres-2025/
LOCATION:Auditorium (AE 005)\, Department of Aerospace Engineering
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/01/Copy-of-Indian-Institute-of-Science-IISc-Dept.-of-Aerospace-Engineering-32-x-64-in-64-x-32-in.pdf-4-1_page-0001_11zon-scaled.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250203T153000
DTEND;TZID=Asia/Kolkata:20250203T170000
DTSTAMP:20260418T154820
CREATED:20250130T070018Z
LAST-MODIFIED:20250130T070404Z
UID:10000051-1738596600-1738602000@aero.iisc.ac.in
SUMMARY:Ph.D. (Engg): Ultrasonic Guided Wave-based Inspection of Additively Manufactured Components
DESCRIPTION:Layered structural components\, such as laminated composites and those made via Additive Manufacturing (AM)\, are widely used in aerospace and automotive industries due to their various advantages. The layer-wise approach allows for intricate and multifunctional designs\, but their performance depends on factors such as joining technique\, material properties\, manufacturing conditions\, and service environments. These layered components are susceptible to defects like delamination\, debonding\, porosity\, residual stress\, cracks\, and surface roughness\, affecting mechanical performance. In AM\, process parameters like laser power\, scan speed\, layer thickness\, hatch spacing\, scan strategies\, solidification strategies\, and build chamber conditions impact the quality of the produced parts. Optimizing these parameters and using in-process monitoring systems can minimize these defects. This thesis focuses on developing an ultrasonics-based monitoring system for AM processes.\nThis work involves the modeling and analysis of wave propagation in multi-layered structures. For this purpose\, three different approaches based on the modeling of interlayer interface bonding have been formulated. The developed models allow for the analysis of different levels of interface bonding\, including perfect bonding and complete debonding. The AM components are idealized as one-dimensional higher-order planar frame structures. The equations of motion are derived from Hamilton’s principle\, and the Fourier transform-based Spectral Finite Element Method (FSFEM) is used to perform the spectral analysis and the spectral elements formulation. The FSFEM formulation results in the dispersion curves and responses in frequency domain\, which is transformed into the time domain by performing the inverse Fast Fourier Transform. A concept of effective thickness is introduced to match the cut-off frequencies in the dispersion curves obtained from the developed approaches with those of exact Lamb waves\, which are used in determining the shear correction factors necessary for higher-order frame formulations.\nThe developed models undergo two levels of validation involving the validation of the dispersion curves\, and time-domain responses. Reference dispersion curves are computed from open-source software for dispersion curve computation\, while the reference time-domain responses are obtained from experiments and the Finite Element simulations.\nFurther\, this thesis focuses on examining the interaction of ultrasonic-guided waves (UGW) with two types of defects – porosity and delamination/debonding. The impact of porosity is analyzed through porosity-dependent constitutive models. Various levels of delamination/debonding are numerically simulated by varying the interface bonding strength in the defect region. Additionally\, the Semi-analytical Finite Element Method is employed to perform spectral analysis of defective structural waveguides with complex geometry\, where the impact of various defect parameters\, such as size\, depth\, and orientation\, have been investigated. Further\, the developed FSFEM models are employed to solve inverse problems for material property characterization\, porosity estimation\, and interface bonding strength characterization. Ultimately\, these models provide a framework for analyzing the dynamic behavior of multi-layered structures\, offering insights into the interaction of UGW with defects. \nAll are welcome. \n  \nSpeaker :   Anoop Kumar Dube \n  \nResearch Supervisor : Prof. S. Gopalakrishnan FNAE FASc\, FIMechE\, CEng
URL:https://aero.iisc.ac.in/event/ph-d-engg-ultrasonic-guided-wave-based-inspection-of-additively-manufactured-components/
LOCATION:Online
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/01/Anoop-.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250210T140000
DTEND;TZID=Asia/Kolkata:20250210T170000
DTSTAMP:20260418T154820
CREATED:20250206T052542Z
LAST-MODIFIED:20250206T052542Z
UID:10000052-1739196000-1739206800@aero.iisc.ac.in
SUMMARY:MTech (Res): Woven composite modeling
DESCRIPTION:In this work\, a novel sub-mesoscale model of woven fabrics is developed using nonlinear finite element methods. The main aim of the work is to develop a framework for modeling woven fabrics. The yarns are modeled as beam elements that move freely in space and undergo large deformations and rotations. A geometrically-exact beam theory (GEBT) used to model composite beams of arbitrary cross sections is considered to model the yarns. The variational asymptotic method (VAM)\, in tandem with the beam model\, offers the advantage of modeling beams of arbitrary cross sections. A surface-to-surface contact model is developed\, considering that the contact occurs at a point on the surface. The robustness of the contact model is tested by designing a patch test. The overall mesoscale model of woven fabric is validated using experimental results of biaxial tests performed on a plain glass weave woven fabric. The biaxial simulation is performed by varying the number of yarns in the mesoscale model to study the behavior of the model and demonstrate a representative volume element (RVE).\nThe yarns are made up of fibers twisted together. An isotropic model is an approximation that works well on the mesoscale\, but a more general model is needed to include fiber-level information. The yarns can be made of 10\,000 to 60\,000 fibers twisted together. Modeling individual fibers and the interaction between them can be computationally expensive. The variational asymptotic method-based homogenization (VAH) is used to get the homogenized properties of yarn. A representative volume element of woven fabric\, with yarns made of coated fibers\, is simulated by using homogenized properties obtained through VAH.\nThe framework can be extended by introducing friction between yarns in the contact. Further\, the uncertainty in the input parameters can be quantified by propagating the uncertainty through the system using uncertainty quantification (UQ) techniques.\n\n\nSpeaker: R Adhithya\n\nResearch Supervisor:  Dineshkumar Harursampath
URL:https://aero.iisc.ac.in/event/mtech-res-woven-composite-modeling/
LOCATION:STC Conference Hall\, Ground Floor\, Department of Aerospace Engineering
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/02/Adhithya.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250218T160000
DTEND;TZID=Asia/Kolkata:20250218T170000
DTSTAMP:20260418T154820
CREATED:20250212T065012Z
LAST-MODIFIED:20250212T065012Z
UID:10000053-1739894400-1739898000@aero.iisc.ac.in
SUMMARY:Ph.D. (Engg): Passive control and intermittent dynamics of the precessing vortex core oscillation in swirl flows
DESCRIPTION:Swirl is used in modern gas turbine combustor nozzles to achieve   reliable flame stabilization and efficient fuel-air mixing. The swirl   component in the nozzle jet flow induces an axial vortex. At high swirl   intensities\, vortex breakdown occurs\, creating a recirculation zone in   the flow known as the vortex breakdown bubble (VBB). VBB appearance is   typically accompanied by the emergence of a global self-excited   instability where the VBB precesses around the flow axis and causes the   axial vortex to form a co-precessing helical structure. This  instability  is referred to as the precessing vortex core (PVC). Several  prior  studies have shown that the PVC oscillation can significantly  impact  emissions and thermoacoustic stability characteristics of the  combustor.  This thesis studies the characteristics and passive control  of the PVC.  The non-reacting flow field in an axial entry swirl nozzle  combustor at  the Massachusetts Institute of Technology (MIT)\, USA\, is  investigated.  Planar three component time resolved velocity field  measurements in the  combustor for combinations of two swirl numbers\, S  = 0.67 and 1.17 and  centrebody diameters of Dc = 9.5 mm\, 4.73 mm and 0  mm (i.e. no centrebody) are analysed. All cases are at a fixed bulk  Reynolds number of 20\,000. A new modal decomposition method based on  wavelet  filtering and proper orthogonal decomposition (WPOD) is  developed in  this thesis to analyze the global non-stationary dynamics  of these  flows. WPOD analysis for configurations without a centrebody  for both  swirl conditions revealed a coherent PVC oscillation in the  flow. Large  eddy simulation (LES) is performed for configurations  without the  centrebody and with the Dc = 9.5 mm centrebody for both  swirl numbers.  For all four cases\, LES accurately captures flow  statistics and PVC  characteristics observed in the corresponding  experimental measurements.  Linear stability analysis (LSA) on the time  averaged flow for each value  of S in the configuration without a  centrebody yields a nearly neutrally  stable global mode whose  oscillation frequency and spatial flow  oscillation amplitude  distribution characteristics match those induced  by the PVC in each  case. The wavemaker region associated with the PVC  mode is shown to be  situated at the upstream end of the VBB on the flow  centreline.  Therefore\, the introduction of a centrebody disrupts the  wavemaker and  suppresses the PVC as the experiments verify. In both LES  and  experimental studies for the cases with the Dc = 9.5 mm centrebody\,  low  amplitude PVC like oscillations\, which are also intermittent in the   S=0.67 case\, are observed. Resolvent analysis (RA) for helical forcing   on the time averaged flow field from LES for these cases is performed.  RA reveals a low rank\, optimal helical mode pair at frequencies where   PVC like oscillations are observed. The output mode amplitude   distribution characteristics match those of the PVC like oscillations  at  both values of S. For the S=0.67 case\, the input mode structure  suggests  that intermittent separation between the centrebody wake and  the VBB\,  due to turbulence results in the startup of PVC oscillations\,  which  subsequent merger then suppresses. For the S=1.17 case\, the input  mode  structure shows that stochastic forcing of the flow by turbulence\,  generated by vortex shedding off the upstream swirler\, results in sustained PVC like oscillations due to a low-rank strongly amplified   flow response at the PVC frequency revealed by resolvent analysis. \n  \nSpeaker: Saarthak Gupta \nResearch supervisor: Prof. Santosh Hemchandra
URL:https://aero.iisc.ac.in/event/ph-d-engg-passive-control-and-intermittent-dynamics-of-the-precessing-vortex-core-oscillation-in-swirl-flows/
LOCATION:Online
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/02/Saarthak-.jpg
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250224T160000
DTEND;TZID=Asia/Kolkata:20250224T170000
DTSTAMP:20260418T154820
CREATED:20250221T055800Z
LAST-MODIFIED:20250221T055800Z
UID:10000054-1740412800-1740416400@aero.iisc.ac.in
SUMMARY:MTech(Res): Adjoint-Based Aerodynamic Shape and Mesh Optimization with High-order Discontinuous Galerkin Methods
DESCRIPTION:The aerodynamic shape of an aircraft plays a critical role in its performance. Aerodynamic Shape Optimization (ASO) modifies the shape to achieve desired performance metrics\, such as reduced drag or increased lift. ASO integrates numerical optimization techniques with Computational Fluid Dynamics (CFD). Gradient-based optimization techniques are widely employed for ASO. The adjoint solution enables the accurate and efficient computation of the gradients of the performance metrics with respect to the shape parameters. Performance metrics are derived from CFD solutions\, which inherently contain inaccuracies. These inaccuracies can affect the reliability of the optimization process. High-order methods\, like Discontinuous Galerkin (DG)\, offer improved accuracy for a computational cost comparable to Finite Volume methods in compressible flows\, making them well-suited for ASO. Adaptive mesh refinement can further improve the accuracy of simulations. The adjoint solution used for computing gradients also finds application in mesh adaptation. Combining adjoint-based mesh adaptation with gradient-based ASO provides better control over the inaccuracies during optimization. \nTowards this\, the present work performs ASO using high-order DG methods and devises strategies for incorporating adaptive mesh refinement. The shape is defined using smooth splines\, and the Free Form Deformation (FFD) method controls shape changes. With changes in the geometry\, the mesh needs to move to be consistent with the modified shape. A mesh deformation strategy ensures that the mesh evolves smoothly with geometry. A gradient-based method employing the Sequential Quadratic Programming (SQP) algorithm is used for optimization. The adjoint solution computes the gradients and passes them to the optimization algorithm. Optimization for a set of drag minimization problems\, including benchmark Aerodynamic Design Optimization Discussion Group (ADODG) test case 1 and inverse design problems\, is performed on non-adapted meshes. \nFurthermore\, a strategy is formulated to incorporate adjoint-based mesh adaptation within the optimization process. Based on the value of adjoint-based error estimates\, the strategy decides on instances of the optimization process that require control of the errors and\, thus\, mesh adaptation. Such a strategy leads to automated control of errors in the performance metrics\, thus improving the reliability and efficiency of the optimization process. \n  \nSpeaker : Pandya Kush Tusharbhai \nResearch Supervisor : Aravind Balan
URL:https://aero.iisc.ac.in/event/mtechres-adjoint-based-aerodynamic-shape-and-mesh-optimization-with-high-order-discontinuous-galerkin-methods-2/
LOCATION:STC Seminar Hall\, Dept. of Aerospace Engineering
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/02/Slide3.jpg
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250305T140000
DTEND;TZID=Asia/Kolkata:20250305T170000
DTSTAMP:20260418T154820
CREATED:20250305T053106Z
LAST-MODIFIED:20250305T053338Z
UID:10000058-1741183200-1741194000@aero.iisc.ac.in
SUMMARY:Ph.D. (Engg): Numerical Studies on the effect of core metal type and thickness on the mechanical behaviour of fiber metal laminates
DESCRIPTION:Fiber Metal Laminates are materials that combine metal properties with Fiber Reinforced Plastics (FRP) to improve mechanical performance. This research investigates the impact of core metal type and thickness on the tensile and impact behavior of FMLs. Initially two types of FML were modeled: GFML based on GFRP and HFML based on CFRP and GFRP. Numerical simulations were performed to predict FMLs’ behavior under low-velocity impact loading. Results showed that hybridization of CFRP with GFRP increased maximum force but reduced maximum displacement and energy absorption. Studies have shown that GFRP and CFRP layer positioning and thickness along the laminate the can enhance contact force and energy absorption\, but enhances the delamination at material interfaces. The importance of optimal stacking sequences is evident as hybridization also causes enhanced delamination. The study also\, examined the effect of the core metal layer thickness on low-velocity impact behavior of FMLs. It found that adding a thicker aluminum layer to the middle of the laminate improves energy absorption and reduces permanent displacement due to higher plastic dissipation. Laminates with thicker aluminum cores also show superior impact resistance\, making them suitable for impact-prone applications. Initial studies found that the metal layer in the fiber metal laminates plays a dominant role in achieving the desired properties. Hence\, the present study focuses on the role of core metal type and its thickness on the tensile\, low velocity\, and high velocity impact behavior of fiber metal laminates. Aluminum 2024 T3 – GFRP-based FML with a titanium 6Al 4V core layer and Titanium 6Al 4V – GFRP-based FML with an aluminum 2024 T3 core layer are considered to study the effect of the core metal layer and its thickness on the tensile and impact behavior of fiber metal laminates. Tensile simulations were performed for different core metal layers with varying thicknesses ranging from 0.8 mm to 2 mm at the core position of the laminate. The results show that aluminum-based FML with a titanium core improves elastic modulus\, yield strength\, ultimate tensile strength\, and failure strain compared to titanium-based FML with an aluminum core. In addition\, the deep neural network has been used to predict the stress-strain curve of FMLs\, focusing mainly on the thickness of the core metal. The DNN results closely match the FEA results. In continuation\, numerical simulations were carried out to study the effect of the type of core metal and its thickness on the low-velocity impact behavior of fiber metal laminates. The results showed that an increase in the thickness of the titanium core in aluminum-based FMLs reduces the energy absorption capacity and the plastic dissipation energy while increasing the maximum force and displacement ratio. The study shows that titanium as the core layer is recommended when the thickness of the titanium layer is less than the total thickness of the aluminum layer. In addition\, numerical simulations were also carried out to evaluate the influence of the core metal type and its thickness on the high-velocity impact behavior of FMLs. The results indicated that the ballistic velocity increases with increasing thickness of the titanium layer. Laminates with thicker titanium layers showed higher impact resistance and energy absorption. This thesis establishes an approach to tailoring FMLs by describing the relationship of fiber hybridization\, core metal type\, and its thickness to achieve desired FML properties. The findings demonstrate the development of innovative hybrid materials with superior impact resistance\, tensile strength\, and energy absorption\, confirming their suitability for demanding engineering applications. \n  \nSpeaker: Sadananda Megeri   \n  \nResearch Supervisor: Narayana Naik G
URL:https://aero.iisc.ac.in/event/ph-dengg-numerical-studies-on-the-effect-of-core-metal-type-and-thickness-on-the-mechanical-behaviour-of-fiber-metal-laminates/
LOCATION:Online
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/03/SADANANDA.jpg
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250305T153000
DTEND;TZID=Asia/Kolkata:20250305T170000
DTSTAMP:20260418T154820
CREATED:20250303T052352Z
LAST-MODIFIED:20250303T052352Z
UID:10000056-1741188600-1741194000@aero.iisc.ac.in
SUMMARY:Multi-fuel combustion for sustainable aviation
DESCRIPTION:With the climate change becoming as one of the main challenges for human existence\, every sector has to contribute in reducing its climate footprint. Being an international and hard to abate sectors\, aviation is struggling to find a viable replacement for kerosene. This talk focuses on a novel multi-fuel combustion strategy that is aimed at making aviation fuel agnostic. This is one of the latest endeavours that we are pursuing at TU Delft along with our industrial partners\, Airbus and Safran. \n  \nSpeaker:  Prof. Arvind G Rao \nBiography : \nDr. Arvind Gangoli Rao\, is a Chair Professor of Sustainable Aircraft Propulsion at the Faculty of Aerospace Engineering\, TU Delft. Dr. Gangoli Rao obtained his masters and PhD in aerospace engineering from the Indian Institute of Technology\, Bombay and later worked at Technion\, Israel as a post-doctoral researcher. Dr. Gangoli Rao is a specialist in aircraft propulsion and has worked on a variety of problems related to gas turbines and novel propulsion systems for aircraft\, especially ones dealing with the usage of alternative energy sources. He has authored around 100 publications. Dr. Gangoli Rao has been involved in several EU projects and Dutch funded projects on sustainable aviation along with the industrial partners. He is the Dutch representative International Society of Air Breathing Engines (ISABE). He is also a member of the ACARE (Advisory Committee for Research and innovation in Europe) working group on Energy and Environment.
URL:https://aero.iisc.ac.in/event/multi-fuel-combustion-for-sustainable-aviation/
LOCATION:Auditorium (AE 005)\, Department of Aerospace Engineering
CATEGORIES:AE Seminar
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/03/Arvind.jpg
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250307T110000
DTEND;TZID=Asia/Kolkata:20250307T130000
DTSTAMP:20260418T154820
CREATED:20250304T093656Z
LAST-MODIFIED:20250304T093656Z
UID:10000057-1741345200-1741352400@aero.iisc.ac.in
SUMMARY:Ph.D. (Engg): Studies on Fluid Structure Interactions in Hypersonic Flow
DESCRIPTION:The global thrust towards the development of hypersonic cruise systems for various applications is leading towards slender configurations with lifting and control surfaces which are thin and complaint and face a hypersonic flow. Hypersonic flows are characterized by large flow kinetic energy and momentum\, which manifests into strong shocks\, high temperatures\, and associated effects that can cause coupling between the flow\, structure\, and thermal effects. Therefore\, understanding Fluid-Structure Interactions (FSI) in hypersonic flow gains significance\, and its predictive modelling is necessary to avoid adverse effects in flight. The majority of literature in supersonic and hypersonic FSI  consider low-fidelity modelling using piston theory\, two-dimensional FSI  computations\, and a limited number of experiments on mainly fully clamped flat panels subjected to aerodynamic loads\, including shock-boundary layer interactions at supersonic Mach numbers. Studies on cantilevered panels\, which are template shapes of control surfaces\, at hypersonic Mach numbers are few\, and there is a significant need to obtain experimental data to aid physical understanding\, validate computational tools and methodology and model the hypersonic FSI  phenomena.\n This motivated the study of three different template flat plate experimental models in the hypersonic shock tunnel HST-2 in the Ludwieg  Mode of Operation\, which has 35 ms of test time. The freestream Mach number of M=6.6 is incident upon a) a cantilevered panel placed along the direction of the flow\, b) a cantilevered panel with an impinging shock\, and c) a trapezoidal wing-like shape fixed at the root and placed transverse to the flow. High-speed schlieren imaging and static pressure measurements at specific locations yield information on the flow characteristics. Image tracking methods are used to extract structural deformation\, and accelerometers measure the oscillatory structural response in the presence of hypersonic flow. Complementary two-dimensional numerical simulations in a fully coupled format are conducted for a limited number of cases. Parametric studies are conducted by varying the panel thickness\, angle of attack\, and mass ratio for plain panels and the impinging shock characteristics for the panel with shock impingement. Natural\, free vibration experiments using an impact hammer excitation are first carried out to evaluate the natural structural modal frequencies.\n Great care is taken in designing all experimental models so that the FSI  response can be captured during the short test time. Oscillatory response is captured successfully using the different diagnostic tools.   For a plain cantilevered panel placed at the Angle of Attack of 20 degrees\,  the FSI response is dominantly near the first structural bending mode at a frequency of 89.65 Hz\, which is higher in comparison to the natural frequency of 75.82 Hz. Multiple diagnostic tools and Dynamic Mode  Decomposition analysis confirm these observations. The angle of attack and mass ratio affect the amplitude of oscillations. Varying thickness changes the structural stiffness\, and accordingly\, the oscillations occur at higher frequencies. Higher downstream pressures on the top surface of the panel due to forebody shock first cause the panel to bend away from the flow\, which leads to the formation of expansion fans\,  releasing the pressure and causing the elastic restoring force to bring it back. Complementary two-dimensional FSI simulations showed good agreement with the experiments\, though the magnitude of amplitude was higher due to the 2D nature of the simulation. Shock Boundary Layer  Interaction is significantly affected by the panel’s compliance. There is a 29.6% reduction of the SBLI separation bubble size on a complaint cantilevered panel. The twin effects of a relaxation in pressure gradient and the existence of wall-normal velocities due to a vibrating panel can be attributed to the observed effect. The trapezoidal wing shape exhibited significantly higher magnitudes in the second structural mode.\nThe studies have laid the foundations for deeper investigations using field imaging techniques like 3D-Digital Image Correlation in the future. The experimental database can be used to develop predictive modelling approaches and data-driven modelling.\n\nSpeaker: Ms. Kartika Ahuja \n\nResearch Supervisor: Prof. Srisha Rao M V
URL:https://aero.iisc.ac.in/event/ph-d-engg-studies-on-fluid-structure-interactions-in-hypersonic-flow/
LOCATION:STC Seminar Hall\, Dept. of Aerospace Engineering
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/03/Kartika.jpg
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250312T150000
DTEND;TZID=Asia/Kolkata:20250312T170000
DTSTAMP:20260418T154820
CREATED:20250307T064034Z
LAST-MODIFIED:20250307T064034Z
UID:10000059-1741791600-1741798800@aero.iisc.ac.in
SUMMARY:Ph.D.(Engg) : Multi-Agent Pursuit-Evasion and Coverage Strategies
DESCRIPTION:Autonomous agents are increasingly being used to solve many tasks\, deemed complex by humans\, with ease and effectiveness. Two such applications are in defense scenarios and in coverage. This thesis\, therefore\, is devoted towards study of motion planning strategies for autonomous agents in the context of pursuit-evasion problems as well as different coverage problems. The thesis comprises two parts. In the first part\, pursuit-evasion is considered between an evader and one or more pursuers\, all the agents being non-holonomic having turn radius constraints. A partial information setting is considered wherein the agents (evader and pursuer) know about each others’ speed and position but not about their turning capability. The objective in these problems\, where the pursuer is of higher speed but less agile\, is to obtain an evasive strategy. A two-phase evasive strategy is proposed as an effective solution against the pursuers. It is a proximity based strategy. In the first phase\, when the pursuer is beyond a critical distance from the evader\, the latter assumes the worst that the pursuer is holonomic and solves for the best response strategy. This phase is called the Worst Case Scenario Planning (WCSP). When the evader is within the critical range from the pursuer\, the former attempts sharp maneuvers to sidestep the pursuer and extend time of capture. This phase is called the Proximity Based Maneuver (PBM). Dynamic programming is used to solve for the WCSP strategy. In case of multiple pursuers\, the concept of dominance regions is used to obtain the WCSP strategy. Additionally\, the pursuit-evasion problem is extended to a reach-avoid problem where the evader has the dual objective of avoiding the pursuer and reaching a target. This thesis considers the problem of reaching a moving but non-maneuvering target by a turn radius constrained evader in the shortest time. The evader is modeled as a Dubins vehicle and the reaching strategy is deduced by studying the time-to-go properties for different strategies and chronologically checking simple conditions at crossover points. The proposed two-phase evasive strategy is used for avoiding the pursuer. The reaching strategy and the avoiding strategy are linearly combined to obtain the net reach-avoid strategy. Extensive simulation results are provided to corroborate the effectiveness of both the evasive and the reach-avoid strategies. In the second part of the thesis static and dynamic coverage problems are discussed. Inspiration from flocking principles with substantial modifications is used to design a static coverage strategy. This ensures that the covering agents are spread uniformly around the structure while avoiding collision among themselves and with obstacles in the environment. Coverage is addressed for convex and non-convex shapes in 2D and 3D. For dynamic coverage\, concept of Lissajous curves is used to achieve coverage. Dynamic coverage is split into two chapters: coverage of planar regions and coverage of 3D structures. For planar regions\, the boundary of the region is approximated using Fourier series and radial Lissajous curves are generated within the boundary as reference coverage paths. The optimal field-of-view size is analytically determined along with the upper-bound on the time taken for complete coverage. Various extensions of the strategy such as preferential coverage and simultaneous coverage are also discussed. For 3D structures\, an enclosing volume is considered and Lissajous curves are generated on the surface of the enclosing volume. Conditions for complete coverage as well as collision free coverage in case of multiple agents are determined analytically. Artificial potential fields are used to obtain coverage by conforming to shape of the structure. A variety of enclosing volumes are discussed along with diverse applications such as patch coverage\, waypoint coverage\, and coverage of moving structures. Performance metrics are proposed for both static and dynamic coverage problems that helps in ascertaining the quality of coverage. \n  \nSpeaker : Suryadeep Nath    \nResearch Supervisor: Debasish Ghose
URL:https://aero.iisc.ac.in/event/ph-d-engg-multi-agent-pursuit-evasion-and-coverage-strategies/
LOCATION:STC Seminar Hall\, Dept. of Aerospace Engineering
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/03/SURYADEEP-.jpg
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250313T150000
DTEND;TZID=Asia/Kolkata:20250313T170000
DTSTAMP:20260418T154820
CREATED:20250311T110524Z
LAST-MODIFIED:20250311T110524Z
UID:10000061-1741878000-1741885200@aero.iisc.ac.in
SUMMARY:Ph.D.(Engg) : Effect of Laser Shock Peening on Residual Stress and Mechanical behaviour of Aluminium alloy AA2219 Friction Stir Weld
DESCRIPTION:Aluminium alloy AA2219 is a precipitation hardenable wrought alloy with copper as a major alloying element. Large-volume propellant tanks of space launch vehicles are manufactured by joining AA2219 aluminium alloy through Friction Stir Welding (FSW) and it is designed optimally to improve the payload capability.  An increase in the strength of the FSW joint results in payload improvement of space launch vehicles. Residual stress is one of the crucial parameters for the design of pressure vessels\, and it is also necessary to mitigate or reduce the same to improve structural margins. The main challenge is understanding the cause of residual stress\, its evaluation\, and mitigation due to the FSW process. Laser shock peening (LSP) is one of the most promising surface modification techniques to improve the performance of weld joints. In the LSP process\, a high-energy laser beam impacts the surface of the specimen and generates ionized plasma by evaporating a thin ablative layer on the specimen. When a high-energy laser pulse passes through the transparent layer and hits the sample\, the thin ablative layer is vaporized and continues to absorb the laser energy resulting in the generation of ionized plasma. Rapidly expanding plasma is entrapped between the specimen and the transparent layer\, generating high surface pressure and propagating into the sample as a shock wave. When the peak pressure exceeds the material’s yield strength\, plastic deformation occurs in the specimen.\n\nThe present work aims to investigate the impact of LSP on residual stress\, microhardness\, global tensile behaviour\, tensile behaviour of various zones (local tensile behaviour)\, stress corrosion cracking behaviour and surface roughness of AA2219 T87 FSW. Surface and through-thickness residual stress were investigated in this work. In as-welded conditions\, tensile residual stress exists in the weld region with a peak value of +123.5 MPa in the Thermo-Mechanically Affected Zone (TMAZ). LSP has significantly affected all the regions of the weld and reduced tensile residual stress to compressive. Longitudinal residual stress is non-uniform through thickness as well as across the weld. Peak tensile residual stress is +160 MPa at the centre of the weld in mid-thickness\, and the LSP process led to a 55% reduction.\n\nAA2219 T87 FSW exhibits a yield strength of 197 MPa and an ultimate tensile strength of 348 MPa at ambient temperature. The LSP process increased the yield strength of the FSW joint by 7 – 14%. A similar increase is seen in cryogenic temperatures also. The increase in the yield strength is due to the strain-hardening effect induced by LSP. The response of different zones of FSW to tensile lading and LSP was investigated using the digital image correlation technique. LSP led to an increase in YS in Weld Nugget and TMAZ. However\, HAZ does not exhibit a significant increase in YS. The LSP process led to an increase in microhardness of 7 – 20%. Single-layer peening has affected < 0.5 mm depth\, whereas three and six layers of peening have influenced a depth of 1.0 mm and more than 2 mm\, respectively. Metallographic study of LSP specimen confirms an increase in dislocation density\, which is the cause for the increase in YS and microhardness.  The LSP process has increased surface roughness in all regions of FSW\, and the increase is substantial in the weld nugget and TMAZ regions. The LSP process has not affected stress corrosion cracking resistance\, irrespective of the number of layers of peening.\n\nIn summary\, a systematic investigation of the effect of LSP on AA2219 T87 FSW joint is carried out using various experimental and characterization techniques and the benefits of LSP are clearly brought out. LSP of AA2219 FSW reduces tensile residual stress and increases YS. This study has also quantified the improvement in YS of various zones of AA2219 FSW due to the LSP. An increase in microhardness was also noticed due to LSP. In addition\, resistance to stress corrosion cracking is not compromised due to LSP. This research outcome will be useful in improving the structural safety margin or reducing the inert mass of aerospace structures and pressure vessels.\n\n\nSpeaker : Dhanasekaran M P\n\n\nResearch Supervisor: Prof. D. Roy Mahapatra
URL:https://aero.iisc.ac.in/event/ph-d-engg-effect-of-laser-shock-peening-on-residual-stress-and-mechanical-behaviour-of-aluminium-alloy-aa2219-friction-stir-weld/
LOCATION:Online
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/03/Dhanasekaran.jpg
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250317T090000
DTEND;TZID=Asia/Kolkata:20250317T173000
DTSTAMP:20260418T154820
CREATED:20250225T055413Z
LAST-MODIFIED:20250225T055413Z
UID:10000055-1742202000-1742232600@aero.iisc.ac.in
SUMMARY:Workshop on Sustainability
DESCRIPTION:The Society for Shock Wave Research (India )\, Department of Aerospace Engineering is organizing a “One Day Workshop on Sustainability in Aerospace”  on Monday\, March 17\, 2025. The primary objective of this workshop is to delve into recent advancements and future challenges in sustainable aerospace technology.\nThe aerospace sector is experiencing significant growth in both aviation and space access. As environmental and sustainability concerns take center stage\, the need for continued growth and expansion in the aerospace sector becomes more pressing. This workshop aims to bring together students\, academics\, industry professionals\, and global experts to engage in discussions focused on innovative solutions for sustainability in propulsion systems\, aircraft designs\, fuels\, and space systems. Technical experts from TU-Delft\, University of Central Florida\, IISc and startups from the Netherlands and India will be delivering expert talks highlighting the frontline research activity towards sustainability in aerospace systems. Ample opportunities for discussions among community members will enable the spawning of new research directions.\nWorkshop Brochure is attached.\n\nInterested participants\, kindly register for the workshop.\n\nPlease contact srisharao@iisc.ac.in / sumittambe@iisc.ac.in for any clarifications.
URL:https://aero.iisc.ac.in/event/workshop-on-sustainability/
LOCATION:Auditorium (AE 005)\, Department of Aerospace Engineering
CATEGORIES:Workshops / Conferences
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/02/WorkshopSustainability.jpg
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250317T110000
DTEND;TZID=Asia/Kolkata:20250317T130000
DTSTAMP:20260418T154820
CREATED:20250311T111336Z
LAST-MODIFIED:20250311T111336Z
UID:10000062-1742209200-1742216400@aero.iisc.ac.in
SUMMARY:The longest known insect migration: Fusing Biology with Aerospace Engineering for innovative solutions
DESCRIPTION:The intriguing annual migration of the dragonfly species\, Pantala flavescens\, was reported a century ago.\nThe multi-generational\, transoceanic migration circuit spanning 14000-18000 kms\, from India to Africa is an\n astonishing feat for an insect few cms in size. Wind\, precipitation\, fuel\, breeding\, and the life cycle affect\n the migration\, yet understanding of their collective role in the migration remains elusive. We identify the\n transoceanic migration route by imposing a time constraint emerging from energetics on Dijkstra’s\npath-planning algorithm. Energetics calculations reveal Pantala flavescens can endure 90 hours of steady\n flight at 4.5m/s. We incorporate active wind compensation in Dijkstra’s algorithm to compute the migration\n route from years 2002 to 2007. The prevailing winds play a pivotal role; a direct crossing of the Indian Ocean\n from Africa to India is feasible with the Somali Jet\, whereas the return requires stopovers in Maldives and Seychelles.\n The migration timing\, identified using monthly-successful trajectories\, life cycle\, and precipitation data\,\ncorroborates reported observations. While working on this problem my mind ventured into many different\n applications of engineering\, which are all connected to the transoceanic migration of dragonflies.\nThe applications range from designing airfoils/wings\, sports aerodynamics and wind turbines to developing\n novel spectral accuracy algorithms for numerical simulations. Hence the ideas vary from simple mimicking\n of dragonflies to more complex abstractions arising from the need to understand their flying behaviour.\n\nSpeaker: Dr Sandeep Saha\n\nBiography :\n\nDr Sandeep Saha is an Associate Professor in the Department of Aerospace Engineering\, IIT Kharagpur.\nHe obtained his bachelors and masters degrees in Mechanical Engineering from IIT Kharagpur.\nHe completed his PhD in Mechanical Engineering from Imperial College London. He thereafter worked as  a\nMarie-Curie Experienced Researcher\, CNRS (Laboratoire FAST)\, Orsay\, France. Thereafter he worked as\n an Aerodynamics Engineer\, ALSTOM Power (now GE)\, Rugby\, UK; then as Research Scientist (Fluids)\,\nSchlumberger Gould Research\, Cambridge\, UK; and then as Academic Staff member\, Mechanical Engineering\,\nUniversity of Duisburg-Essen\, Germany (in collaboration with SIEMENS AG). He has worked on a range of\n problems in fluid mechanics and in recent years has focused on Low Reynolds number Aerodynamics\n ranging a broad spectrum of problems like insect flight\, extraterrestrial flight\, respiratory flows and\nwaste heat recovery and sports aerodynamics.
URL:https://aero.iisc.ac.in/event/the-longest-known-insect-migration-fusing-biology-with-aerospace-engineering-for-innovative-solutions/
LOCATION:STC Seminar Hall\, Dept. of Aerospace Engineering
CATEGORIES:AE Seminar
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/03/Sandeep.jpg
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250318T110000
DTEND;TZID=Asia/Kolkata:20250318T130000
DTSTAMP:20260418T154820
CREATED:20250311T060827Z
LAST-MODIFIED:20250311T060827Z
UID:10000060-1742295600-1742302800@aero.iisc.ac.in
SUMMARY:Ph.D.(Engg): Investigations on Hypersonic Laminar to Turbulent Boundary Layer Transition in a Shock Tunnel.
DESCRIPTION:The laminar to turbulent boundary layer transition onset has perplexed fluid dynamics community irrespective of the flow regime under which the phenomenon is probed. The complexity of the problem is compounded in high-speed compressible flows where in the transition onset location is a strong function of many subtle factors like freestream quality\, surface roughness\, wall temperature etc. The transitional and turbulent boundary layers bring their typical characteristics\, like an increase in skin friction\, heat transfer\, fluid dynamic parameters fluctuations\, mixing characteristics\, potential to negotiate adverse pressure gradient\, along with them. These typical characteristics of transitional and turbulent boundary layers can be both detrimental and advantageous to a given facet of an aerodynamic vehicle design. Hence the boundary layer transition onset location is one of the key design inputs in the development of aerodynamic vehicles operating in subsonic\, supersonic and hypersonic freestream environment. A plethora of work has been conducted to investigate the transition onset phenomena in supersonic and hypersonic flow regime since the beginning of space age and the inception of the idea of an air breathing hypersonic cruise vehicle. The outcomes of these investigations and studies on high-speed boundary layer transition onset although led to the development of several techniques and correlations to estimate the transition onset location\, applicable usually to a particular test model and freestream condition\, very few studies targeted the characterization of transitional boundary layer in hypersonic flow regime. The earlier and contemporary work on roughness induced transition onset focused on the effect of the said roughness element on transition onset location but the features associated with the instabilities thus generated by these roughness elements have seldom been reported in the open literature. Hence characterization of transitional boundary layer and the instabilities associated with the same was one of the primary objectives of the present work.\nThe present work on hypersonic boundary layer transition was conducted in a shock tunnel HST4 by employing generic test models like flat plate\, cone and elliptic cone. The work began with the design\, development and deployment of a new contoured nozzle\, with a nominal Mach number of 6.0\, for HST4. Before embarking on the boundary layer transition studies\, dedicated efforts were made to characterize the freestream noise environment of the test section of HST4 by employing experimental and numerical methods. A two-dimensional finite difference Navier-Stokes solver was developed in order to numerically compute the transfer functions required to retrieve freestream pressure fluctuations from the experimental measurements. The RMS of pressure fluctuations in the test section of HST4 was found to be 4.32% for the freestream Reynolds number of 4.5 million/m with major contribution of low frequency fluctuations (<50 kHz) towards the aforementioned RMS magnitude. The transitional boundary layer on smooth surface of a flat plate and an axisymmetric cone were characterized by experimentally measuring the intermittency associated with such boundary layers. The intermittent nature of the transitional boundary layer results from the convection of the turbulent spots along the boundary layer. The leading edge and trailing edge velocities associated with these turbulent spots as well as their generation rates were experimentally measured and computed. The second mode instabilities\, a typical characteristic of high Mach number boundary layers\, were also measured in terms of pressure fluctuations and the bandwidth of these instabilities was found to be in the range of 240-480 kHz. The wavelengths associated with these instabilities were found to be 2.5 times the local boundary layer thickness. Transition onset due to the presence of an isolated roughness element\, either a protrusion or a three-dimensional shoe box cavity\, was also investigated as part of the present campaign. Both isolated protrusion and cavity led to an early onset of transition when compared to the smooth test models with no isolated roughness element. In the case of transition onset due to an isolated cubic protrusion\, the Shuttle Orbiter correlations were found to be inadequate in estimating the transition onset and correlations based on the present dataset were formulated. A single frequency oscillation with a narrow bandwidth centered around 23 kHz corresponding to hair pin vortices in the wake of roughness element was found in the present work. It was also found that while the protrusion suppressed the second mode instabilities\, the cavity aided in the development of high frequency instabilities akin to second mode. Finally initial findings of the transition onset due to cross flow instabilities in an elliptic cone were also discussed in the present work. \n  \nSpeaker : Ankit Bajpai \n  \nResearch Supervisor : Prof. Gopalan Jagadeesh
URL:https://aero.iisc.ac.in/event/ph-d-engg-investigations-on-hypersonic-laminar-to-turbulent-boundary-layer-transition-in-a-shock-tunnel/
LOCATION:STC Seminar Hall\, Dept. of Aerospace Engineering
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/03/Ankit-.jpg
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250319T150000
DTEND;TZID=Asia/Kolkata:20250319T170000
DTSTAMP:20260418T154820
CREATED:20250313T105656Z
LAST-MODIFIED:20250326T050053Z
UID:10000063-1742396400-1742403600@aero.iisc.ac.in
SUMMARY:MTech(Res) : Elastic Wave Dispersion Analysis and Mode Shape Investigation of Higher-order Beam Theory for Thick Beams
DESCRIPTION:The dynamic behavior of structural components over broad frequency ranges\, particularly thick beams under different constraints\, is important in many engineering applications where reduced dimensional modeling is required for design. Applications are aerospace structures\, mechanical systems and civil infrastructure. The rigid cross-section assumption in Euler-Bernoulli and even third-order beam theories cannot accurately capture the effects of stress-free or finite surface conditions and higher-order stress distribution under dynamic situations. While some higher-order beam theories satisfy shear stress boundary conditions\, they do not fully account for normal stress. The higher-order beam theory employed in this study addresses these limitations. It satisfies both shear and normal traction conditions simultaneously. Another problem in guided wave behavior within thick beams is accurately modeling consistent surface or interior dynamics. For this\, the transverse displacement is approximated using a trigonometric variation across the thickness\, characterized by a fundamental wave vector consistent with the necessary stress variation throughout the thickness\, which is particularly relevant for thick structures.\n\nThere remains a lack of comprehensive comparison between different reduced-order models\, particularly in terms of their accuracy in predicting wave dispersion characteristics and dynamic deformation mode shapes in the short and long wavelength limits to evaluate the acceptability of specific models in specific applications. Also\, the choice of beam theory directly influences these properties. This study compares four different theories: Euler-Bernoulli\, Timoshenko\, Third-order shear\, and proposed higher-order theory with surface constraints. The dispersion characteristics of each beam theory are obtained by solving the characteristic equations using the polynomial eigenvalue method\, and dispersion curves are plotted to compare wave propagation behavior predicted by different theories. This comparison highlights the limitations of the lower-order theories\, especially in their ability to accurately capture the behavior of thick beams\, and demonstrates how higher-order theory provides improved predictions of wave behavior.\n\nTwo numerical validation techniques are employed to validate and investigate higher-order wave modes present in higher-order beam theory: one is based on the two-dimensional Fast Fourier Transform (2D FFT)\, and the other uses particle displacement vector plots. In the first approach\, a time-varying excitation is applied to the beam with a specific tonal frequency\, and time-domain response data is collected. The 2D FFT is then performed to extract the dominant wave modes. This method generates the flexural and axial modes at 300kHz frequency as an example\, which is better predicted using the higher-order beam theory. In the second approach\, wave motion is visualized as particle trajectories by plotting displacement components along axial and transverse directions. This method enables the generation of pure wave modes by solving the displacement field directly\, eliminating dependencies on boundary conditions and external excitation. This method validates all mode shapes present in the Higher-order beam theory.\n\nIn summary\, this thesis presents a comparative study of various beam theories to highlight the importance of higher-order beam theories where relevant physics needs to be captured. The dynamic effects are relevant in applications in vibrating machinery\, dynamic contact effects\, bearings\, and advanced contact force-based testing like resonance and force microscopy.\n\n\nSpeaker : Kratika Raje\n\nResearch Supervisor: Prof. D. Roy Mahapatra
URL:https://aero.iisc.ac.in/event/mtechres-elastic-wave-dispersion-analysis-and-mode-shape-investigation-of-higher-order-beam-theory-for-thick-beams/
LOCATION:Online
CATEGORIES:Thesis Colloquium / Defence
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/03/Kratika-1-1.jpg
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250327T100000
DTEND;TZID=Asia/Kolkata:20250327T113000
DTSTAMP:20260418T154820
CREATED:20250321T092005Z
LAST-MODIFIED:20250326T050121Z
UID:10000064-1743069600-1743075000@aero.iisc.ac.in
SUMMARY:Challenges and Strategies for Machining Aerospace High-Temperature Materials
DESCRIPTION:Abstract:\nThe presentation opens with a comparison of high-temperature materials with everyday metals. This will be followed by a discussion of challenges and an understanding of the machinability of high-temperature materials. Next\, various strategies for machining high-temperature materials\, along with practical real-life case studies\, will be presented. We will be introducing the concept of Feed Milling and its advantages. Pocket Milling is among challenging operations\, and we will discuss existing and alternate methods of pocket milling. Finally\, we will discuss the Barrel mill concept for faster profile machining and a few other solutions. \nSpeaker: H R Narasimhan \n  \nBiography:\nH R Narasimhan is currently a Business Development Manager at ISCAR Metalworks\, a multinational metal-cutting tools company affiliated with one of the world’s largest metalworking conglomerates\, the IMC Group (International Metalworking Companies). He has over 25 years of experience in the US Aerospace Industry in Los Angeles\, Oregon\, Seattle\, and Salt Lake City areas\, with several years of experience as National Product Manager for milling and specializing in machining high-temperature materials and composites
URL:https://aero.iisc.ac.in/event/challenges-and-strategies-for-machining-aerospace-high-temperature-materials/
LOCATION:Auditorium (AE 005)\, Department of Aerospace Engineering
CATEGORIES:AE Seminar
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/03/Narasimhan.jpg
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20250327T150000
DTEND;TZID=Asia/Kolkata:20250327T163000
DTSTAMP:20260418T154820
CREATED:20250327T063920Z
LAST-MODIFIED:20250327T063920Z
UID:10000065-1743087600-1743093000@aero.iisc.ac.in
SUMMARY:Laser Beam Control Through Atmospheric Turbulence
DESCRIPTION:Laser beam is highly affected by prevailing atmospheric conditions and limit the system performance for various applications. The talk mainly covers the cause of optical turbulence\, its effects on laser beam and further discuss the technologies for controlling the beam for enhancing the effectiveness. Two main techniques namely the Tip-tilt correction for maintaining the beam at same position and adaptive optics technology for controlling the phase distortions and thus enhancing the signal strength on the receiver plane will be discussed. The experimental results for long range propagation will also be presented and discussed. \n  \nSpeaker: Dr. Amit Pratap\, Sc F\, CHESS (DRDO)
URL:https://aero.iisc.ac.in/event/laser-beam-control-through-atmospheric-turbulence/
LOCATION:STC Seminar Hall\, Dept. of Aerospace Engineering
CATEGORIES:AE Seminar
ATTACH;FMTTYPE=image/jpeg:https://aero.iisc.ac.in/wp-content/uploads/2025/03/Amit.jpg
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END:VCALENDAR