Ahilan Appar

Ahilan Appar received his PhD (2023) and Master’s (2017) degrees in Aerospace Engineering from the Indian Institute of Technology Kanpur, and his Bachelor’s degree (2014) in Aeronautical Engineering from the Madras Institute of Technology, Chennai.

His research focuses on hypersonic reentry aerothermodynamics and rarefied gas dynamics, with an emphasis on developing multiscale and multiphysics models for high-speed flows. He integrates particle methods, such as molecular dynamics (MD) and direct simulation Monte Carlo (DSMC) methods, to study gas–surface interactions (GSI) and flow behavior relevant to hypersonic vehicles and spacecraft operating in very low Earth orbit (VLEO).

He recently developed a GSI model to capture the interaction of atomic oxygen (AO) with the satellite surface in orbital flow applications. He is currently developing specific material-AO interaction models to scale-bridge atomistic interactions into large-scale flow simulations, enabling the study of orbital systems. Previously, he developed computational frameworks for aerothermodynamic reentry of reentry vehicles, addressing material response modeling, ablation phenomena, and transpiration cooling effects. His work also established flow–thermal stability criteria for strongly coupled ablation problems in hypersonic systems.

His broader research interests include reentry aerothermodynamics, gas–surface interaction modeling, and rarefied flow physics.