Topic 1: High performance computing of thermally stratified free shear layers:;

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1.1. Rayleigh Taylor instability: Our research group is involved in performing high-resolution simulations of the buoyancy-driven Rayleigh-Taylor instability to gain inferences about the flow physics from the onset to fully developed turbulent state. A part of this work is being computed using the supercomputer at IISc Bangalore, PARAM PRAVEGA with 4.19 billion mesh points and 19,200 cores under the National Supercomputing Mission.

Publications:

[1] Sundaram, P. et al., A non-overlapping high accuracy parallel subdomain closure for compact scheme: Onset of Rayleigh-Taylor instability by ultrasonic waves. J. Comput. Phys., 470, 11593 (2022).

[2] Sengupta, A. et al., Three-dimensional direct numerical simulation of Rayleigh–Taylor instability triggered by acoustic excitation. Phys. Fluids, 34(5), 054108 (2022).

[3] Sengupta, A. et al., Role of non-zero bulk viscosity in three-dimensional Rayleigh-Taylor instability: Beyond Stokes’ hypothesis. Comput. Fluids, 225, 104995 (2021).

[4] Sengupta, T. K. et al., Roles of bulk viscosity on Rayleigh-Taylor instability: Nonequilibrium thermodynamics due to spatiotemporal pressure fronts. Phys. Fluids, 28, 094102 (2016).

[5] Sengupta, T. K. et al., Non-equilibrium thermodynamics of Rayleigh-Taylor instability. Int. J. Thermophysics, 37(4), 1-25 (2016).

1.2. Kelvin-Helmholtz Rayleigh-Taylor instability: We are focusing on direct numerical simulations of this canonical hydrodynamical instability to explain the competing mechanisms in the flow viz. buoyancy-driven RT and shear-driven KH. Inferences about the dominating flow physics are obtained using a compressible enstrophy transport equation.

Publications:

[1] Sengupta, A. et al., Three-dimensional direct numerical simulation of Rayleigh–Taylor instability triggered by acoustic excitation. Phys. Fluids, 34(5), 054108 (2022).

Topic 2: Control of transonic shock boundary layer interactions using thermal/vortical controls:;

Implicit large eddy simulations are performed to show control of shock and boundary layer interactions over a natural laminar flow airfoil by thermal and vortical controls located on suction surface at a free-stream Mach number, 0.72 and angle of attack of 0.38o, for which experimental/flight test results exist

Publications:

[1] Sengupta, T. K. et al., Thermal control of transonic shock-boundary layer interaction over a natural laminar flow airfoil. Physics of Fluids, 33, 126110 (2021).

[2] Sengupta, T. K. et al., Comparative study of transonic shock–boundary layer interactions due to surface heating and cooling on an airfoil. Physics of Fluids, 34(4), 046110 (2022).

[3] Chakraborty, A. et al., Controlling transonic shock-boundary layer interactions over a natural laminar flow airfoil by vortical and thermal excitation. Phys. Fluids, 34(8), 085124 (2022).