Nonlinear saturation of Mack modes in a hypersonic boundary layer

Some decades ago J. T. Stuart formulated a theory for nonlinear saturation of hydrodynamically unstable modes. He proposed that an unstable mode, upon gaining sufficient energy, distorts the mean flow. This mean flow distortion reduces the shear, thus reducing the inviscid energy production mechanism which eventually results in a saturation of instability. In a hypersonic boundary layer, Mack modes, which have an acoustic as well as a vortical structure, saturate with a different mechanism. In this talk I will present the Mack mode instability saturation mechanism using parallel flow DNS and models. I will also give a brief overview of the other ongoing research activity in my group at IIT Delhi.

Speaker: Dr. Prateek Gupta

Biography :

Dr. Gupta is an Assistant Professor at the Department of Applied Mechanics, IIT Delhi. He completed his BTech in Mechanical Engineering from IIT Delhi in 2015 and PhD in Mechanical Engineering at Purdue University in 2019. He performed theoretical and numerical investigations of nonlinearities in thermoacoustic systems for this PhD thesis. He later joined the Mechanical and Process Engineering Department at ETH Zurich as a Postdoctoral Fellow, where he worked on theoretical and computational modeling of non-equilibrium thermodynamics in crystalline materials. He joined the faculty of his alma mater in 2021. Dr. Gupta’s broad research interests span fundamentals and applications of fluid mechanics, statistical mechanics, and thermodynamics.