IISc Bangalore

D. Sivakumar

Associate Professor
Email: dskumar[at]iisc.ac.in
Office Phone Number: +91-80-22933022
Lab Phone Number: +91-80-22933098
Office Room Numbe: AE133
Lab Room Number : AE033



Ph.D. Aerospace Engineering, Indian Institute of Science (1999)
M.E. Aerospace Engineering, Indian Institute of Science (1994)
B.Tech. Aeronautical Engineering, Madras Institute of Technology (1992)


  • Associate Professor (January 2011 onwards), Department of Aerospace Engineering, Indian Institute of Science
  • Visiting Researcher (June 2009 – July 2009), Institute of Fluid Science, Tohoku University
  • Assistant Professor (January 2005 – December 2010), Department of Aerospace Engineering, Indian Institute of Science
  • JSPS Postdoctoral Researcher (April 2003 – December 2004), Institute of Fluid Science, Tohoku University
  • Alexander von Humboldt Research Fellow (2001 – 2002), Institute for Fluid Mechanics and Aerodynamics, Technical University of Darmstadt
  • Research Associate (March 2000 – December 2000), Department of Aerospace Engineering, Indian Institute of Science
  • Postdoctoral Fellow (1999), Department of Mechanical Engineering, Georgia Institute of Technology


  • Teaching courses
  • 2005-2007: AE 245 – Mechanics and Thermodynamics of Propulsion (Jointly with Prof. K.N. Lakshmisha)
  • 2005-2008: AE 271 – Flight Vehicle Design (Participated along with other faculties)
  • 2008 – 2011: AE 245 – Mechanics and Thermodynamics of Propulsion
  • 2010 – 2012: AE 248 – Rocket Propulsion (Jointly with Prof. B.N. Raghunandan and Dr. Charlie Oommen)
  • 2010  onwards: AE 276 – Experimental Techniques (Participated along with other faculties)
  • 2013 onwards: AE 276 – Experimental Techniques (Coordinating the course)
  • 2013  onwards: AE 247 – Aircraft Engines (Jointly with Prof. T.S. Sheshadri)

Research Interests

Atomization of liquid jets and sheets – Experimental characterization of engine sprays – Biofuel sprays – Interaction of liquid drops with solid surfaces – Effects of surface texture on the outcomes of impinging liquid drops – Wetting behavior of hydrophobic and superhydrophobic solid surfaces

Research Statement

Combustion phenomenon and its influence on the performance of aircraft and liquid propellant rocket engines are predominantly governed by the atomization process of liquid fuel/propellants. Fuel atomization inside an engine combustion chamber is a complex fluid dynamic process involving several sub-processes such as liquid jet/sheet instability, ligament breakup, jet/sheet interaction with surrounding ambient environment, mixing, spray-wall interaction, and secondary atomization. These sub-processes seen in the spray formation require specific attention and are approached in our laboratory via experimental methods. An integration of these phenomena in the fuel spray dynamics would aid the development of more reliable models of engine combustion.Current research topics
Liquid jets discharging from non-circular orifices : Spray formation via non-circular orifices received significant interest in the context of MEMS (Micro Electro Mechanical Systems)-based fuel injection systems. The current level of understanding on the effect of orifice shape is far from completion as most of the published works are confined to circular orifice. The present research at our laboratory aims to understand the role of orifice exit shape on the spray formation process. Experiments have been conducted with specially prepared non-circular orifices of different shapes (circular, elliptical, rectangular, square, and triangular). Measurements have been collected on the flow and breakup features of water jets discharging from these orifices for a wide range of test conditions. A major contribution of this study is the elucidation of the precise role of axis-switching on the destabilization of elliptical liquid jets.
Spray formation in gas-centered swirl coaxial (GCSC) atomizers: Coaxial atomizers have been widely used in liquid propellant rocket engines with different combinations of liquid and gas jets to enhance the mixing and atomization of fuel and oxidizer. A gas-centered swirl coaxial (GCSC) atomizer discharges an outer swirling liquid sheet and a central gaseous jet from the outer and inner orifices of the atomizer respectively. Experiments have been conducted in the laboratory using water and air as simulants by employing custom fabricated GCSC atomizers with different geometrical parameters. The research study attempts to understand the following: the breakup of outer liquid sheet by the central air jet, the characteristics of spray discharging from GCSC atomizers, the effect of orifice recess on spray formation from GCSC atomizers, etc.
Biofuel sprays: Bio-derived alternative fuels for aviation, produced from biomass sources such as camelina, jatropha, and algae, have received considerable interest in recent years in the context of limiting the level of CO2 emission in atmosphere and ensuring future fuel supply security. Although such fuels are not so different from the conventional jet fuels (for example Jet A-1) in terms of physical properties such as density, viscosity, surface tension, etc., the changes in the chemical ingredients of these newly processed jet fuels warrant an in-depth analysis on the suitability of such fuel sprays in engine combustors. We analyze the atomization characteristics of such fuels from injectors employed in aircraft engines.
Impact of liquid drops on groove-textured solid surfaces: The phenomenon of drop impact on solid surfaces is encountered in a variety of practical applications, from aerospace (ice formation on aircraft surfaces) to zoological (rain drops impact on the wings of insects). Despite the known influence of surface topographical features on the drop impact process, the current understanding on the role of surface texture on the drop impact process is far from completion. Our research analyzes the impact of water drops on stainless steel surfaces comprising micro unidirectional parallel grooves. As part of this research, experiments have been conducted to understand the impact outcomes of impinging liquid drops on stainless steel surfaces comprising unidirectional parallel grooves. Attempts have been made to support the experimental findings via simple theoretical models.

Current Projects


  1. Vaikuntanathan, V., Kannan, R., and Sivakumar, D.. An experimental study on the equilibrium shape of water drops impacted on groove-textured surfaces. Expt. Thermal Fluid Sci. . 87. 129-140. 2017
  2. Sen, S., Vaikuntanathan, V., and Sivakumar, D.. Impact dynamics of alternative jet fuel drops on heated stainless steel surface. Int. J. Thermal Sci.. 121. 99-110. 2017
  3. Vaikuntanathan, V. and Sivakumar, D.. Maximum spreading of liquid drops impacting on groove-textured surfaces: Effect of surface texture. Langmuir. 32. 2399-2409. 2016
  4. Vaikuntanathan, V. and Sivakumar, D.. Effect of wetting difference across junction on dynamics of drops impacting on the junction of dual-textured surfaces. AIChE J. 61. 4109-4118. 2016
  5. Gupta, R., Vaikuntanathan, V., and Sivakumar, D.. Superhydrophobic qualities of an aluminum surface coated with hydrophobic solution NeverWet. Colloids Surf. A . 500. 45-53. 2016
  6. Sivakumar, D., Vankeswaram, S.K., Sakthikumar, R., Raghunandan, B.N., Hu, J.T.C., and Sinha, A.K.. An experimental study on jatropha-derived alternative aviation fuel sprays from simplex swirl atomizer. Fuel. 179. 36-44. 2016
  7. Rajesh, K.R., Sakthikumar, R., and Sivakumar, D.. Interfacial oscillation of liquid jets discharging from non-circular orifices. Int. J. Multiphase Flow . 87. 1-8. 2016
  8. Sivakumar, D., Sakthikumar, R., Raghunandan, B.N., Hu, J.T.C., Puri, S.K., and Jain, A.K.. Atomization characteristics of camelina-based alternative aviation fuels discharging from dual-orifice injector. J. Engg. Gas Turbines Power . 137. 081503. 2015
  9. Sivakumar, D., Vankeswaram, S.K., Sakthikumar, R.,and Raghunandan, B.N.. Analysis on the atomization characteristics of aviation biofuel discharging from simplex swirl atomizer. Int. J. Multiphase Flow . 72. 88-96. 2015
  10. Vaikuntanathan V, Sivakumar D. Transition from Cassie to impaled state during drop impact on groove-textured solid surfaces. Soft Matter. 2014;10. 2014
  11. Sen S, Vaikuntanathan V, Sivakumar D. Experimental investigation of biofuel drop impact on stainless steel surface. Exp. Thermal Fluid Sci. 2014;54. 2014
  12. Unnikrishnan PK, Vaikuntanathan V, Sivakumar D. Impact dynamics of high Weber number drops on chemically modified metallic surfaces. Colloids Surf. A. 2014;459. 2014
  13. Vaikuntanathan V, Sivakumar D. Directional motion of impacting drops on dual-textured surfaces. Physical Rev. E. 2012;86. 2012
  14. Sivakumar D, Kulkarni V. Regimes of spray formation in gas-centered swirl coaxial atomizers. Exp. Fluids. 2011;51. 2011
  15. Kannan R, Vaikuntanathan V, Sivakumar D. Dynamic contact angle beating from drops impacting onto solid surfaces exhibiting anisotropic wetting. Colloids Surf. A. 2011;386. 2011
  16. Kulkarni V, Sivakumar D, Oommen C, Tharakan J. Liquid sheet breakup in gas-centered swirl coaxial atomizers. J. Fluids Engg. 2010;132. 2010
  17. Vaikuntanathan V, Kannan R, Sivakumar D. Impact of water drops onto the junction of a hydrophobic texture and a hydropholic smooth surface. Colloids Surf. A. 2010;369. 2010
  18. Kasyap TV, Sivakumar D, Raghunandan BN. Flow and breakup characteristics of elliptical liquid jets. Int. J. Multiphase Flow. 2009;35. 8-19. 2009
  19. Kasyap TV, Sivakumar D, Raghunandan BN. Breakup of liquid jets emanating from elliptical orifices at low flow conditions. Atomization and Sprays. 18. 645-668. 2008
  20. Kannan R, Sivakumar D. Impact of liquid drops on a rough surface comprising microgrooves. Exp. Fluids. 44. 927-938. 2008
  21. Kannan R, Sivakumar D. Drop impact process on a hydrophobic grooved surface. Colloids Surf. A. 317. 694-704. 2008
  22. Sivakumar D, Katagiri K, Sato T, Nishiyama H. Spreading behavior of an impacting drop on a structured rough surface. Phys. Fluids. 17. 100608. 2005
  23. Sivakumar D, Nishiyama H. Analysis of Madejski splat-quench solidification model with modified initial conditions. J. Heat Transf. 126. 485-489. 2004
  24. Sivakumar D, Nishiyama H. Spreading and solidification of a molten metal droplet impinging on a solid surface. Int. J. Heat Mass Transf. 47. 4469-4478. 2004
  25. Sivakumar D, Nishiyama H. Numerical analysis on the impact behavior of molten metal droplets using a modified splat-quench solidification model. J. Heat Transf. 126. 1014-1022. 2004
  26. Sivakumar D, Raghunandan BN. Formation and collapse of merged liquid sheets from the mixing of coaxial swirling liquid sheets. Phys. Fluids. 15. 3443-3451. 2003
  27. Sivakumar D, Raghunandan BN. Converging swirling liquid jets from pressure swirl atomizers. Phys. Fluids. 14. 4389-4398. 2002
  28. Sivakumar D, Tropea C. Splashing impact of a spray onto a liquid film. Phys. Fluids. 14. L85-L88. 2002
  29. Sivakumar D, Raghunandan BN. Role of geometric parameters on the drop size characteristics of liquid-liquid coaxial swirl atomizers. Atomization and Sprays. 8. 547-564. 1998
  30. Sivakumar D, Raghunandan BN. Hysteretic interaction of conical liquid sheets from coaxial atomizers: Influence on the spray characteristics. Phys. Fluids. 10. 1384-1397. 1998
  31. Sivakumar D, Raghunandan BN. A study of converging thin annular jets. J. Fluids Engg. 119. 923-928. 1997
  32. Sivakumar D, Raghunandan BN. Jet interaction in liquid-liquid coaxial injector. J. Fluids Engg. 118. 329-334. 1996

Current Students

21. Siddharth Jalindar Bangale (Ph.D.)

20. Kukkarasi Ramana (Ph.D.) (Jointly with Prof. R.N. Gavardhan through ME)

19. Kumar Gaurav (Ph.D.)

18. M. Chandrasekhar (Ph.D.) (Jointly with Prof. R.N. Govardhan through ICER)

17. Sai Krishna Vankeswaram (Ph.D.)

16. K.R. Rajesh (ERP Ph.D.)

Former students

15. Pallav Kesarwani, Ph.D. (Jointly with Prof. R.V. Ravikrishna through ICER), 2022

14. Vishal Singh, M.Tech. (Research)) (Jointly with Prof. S. Chaudhuri), 2021

13. Akshay, S., M.Tech. (Research)), 2021

12. Narendra Dev, M.Tech. (Research), 2020

11. Athul Joseph, Ph.D., 2020

10. Maanasa Bhat, M.Tech. (Research), 2018 (currently Ph.D. student at Massachusetts Institute of Technology)

9. Viverjita, U., M.Sc. Engg., 2017 (currently Ph.D. student at Virginia Tech)

8. Rahul Gupta, M.Sc. Engg., 2017, awarded best department MSc thesis medal

7. Visakh Vaikuntanathan, Ph.D., 2016, awarded best department PhD thesis medal (currently doing post-doc at University of Stuttgart)

6. Sai Krishna Vankeswaram, M.Sc. Engg., 2015, awarded best department MSc thesis medal

5. Adul Sankar, M.Sc. Engg., 2015

4. Visakh Vaikuntanathan, M.Sc. Engg., 2011

3. R. Kannan, Ph.D., 2012 (completed post-doc from University of Toronto and currently at Amrita School of Engineering, Coimbatore, India)

2. Varun Kulkarni, M.Sc. Engg., 2010 (completed Ph.D. from Purdue University)

1. T.V. Kasyap, M.Sc. Engg, 2009, awarded best department MSc thesis medal (completed Ph.D. from Cornell University)

This will be updated soon.