Speaker: John Bell, Lawrence Berkeley National Laboratory
Location: Warren Weaver Hall 1302
Date: Oct. 29, 2010, 10 a.m.
A number of problems in astrophysics are characterized by low Mach number flows. Examples include the convection phase in a white dwarf prior to ignition of a Type Ia supernova, X-ray bursts and convection in massive stars. Low Mach number models analytically remove acoustic wave propagation while retaining compressibility effects resulting from nuclear reactions and ambi- ent stratification. This enables time steps controlled by advective time scales, resulting in significant reduction in computational costs. We will discuss the derivation and basic discretization methodol- ogy for low Mach number models for astrophysical applications and present computational results illustrating application of the methodology, focusing on the convection leading up to ignition in a Type Ia supernova.