The Kelvin-Helmholtz (KH) instability is a prototypical hydrodynamic mixing process driven by velocity shear. I will present simulations of the KH instability in compressible hydrodynamics. Compressibility introduces baroclinic instabilities which can further enhance mixing. I compare simulations run at specific Reynolds numbers to "implicit large eddy simulations'' (ILES) in which numerical errors play the role of a sub-grid scale diffusivity parameterization. Many of the simulations were run using Dedalus, an open-source spectral code which can solve nearly arbitrary PDEs. I will then discuss extrapolating our simulations to the limit of Re->infinity, extrapolating the ILES to the limit of resolution approaching infinity, and whether or not these two limits are the same.
Analysis of Fluids and Related Topics: Mixing in Compressible Hydrodynamics as Diffusivities Approach Zero
Daniel Lecoanet , Princeton University
Mar 16 2017 - 4:30pm
Analysis of Fluids and Related Topics
Fine Hall 322