Multiscale modeling for hypersonic rarefied flows

Abstract:

Flows around high-altitude aerospace vehicles can exhibit large variations in the molecular mean free path lengths. In these multiscale flows, conventional Navier-Stokes-Fourier description, on which continuum flow solvers are based, breaks down where the Knudsen number becomes large. Rarefied flows need to be modeled using the Boltzmann equation, which resolves the molecular nature of the gas. The Boltzmann equation is not amenable to analytical solution, and it presents overwhelming difficulties to conventional numerical methods due to non-linearity of the collision operator and the high dimensionality of the solution domain. Therefore, it is important to develop accurate and efficient numerical schemes to solve the Boltzmann equation. In this seminar, I will present numerical analysis for both equilibrium and non-equilibrium flows based on statistical methods; Direct Simulation Monte Carlo (DSMC), Low Diffusion (LD), and including works using the Fokker-Planck (FP) will be discussed. Novel `all-particle' schemes are applied to aerospace problems; hypersonic entry flows and rarefied plume flow.

Bio:

Dr. Jun is a postdoctoral research associate at the University of Edinburgh. She earned a PhD of Aerospace Engineering at the University of Michigan, Ann arbor, and she worked for Samsung as a production senior engineer, DLR (German Aerospace Center) as a Postdoc.