5–6 nov. 2015
Université Paris Descartes
Fuseau horaire Europe/Paris
List of accepted contributions for the poster session available!

Low Mach Number Modeling of Stratified Astrophysical Flows

6 nov. 2015, 14:00
45m
Amphi Lavoisier A, 3rd floor (Université Paris Descartes)

Amphi Lavoisier A, 3rd floor

Université Paris Descartes

45 rue des Saints Pères 75006 PARIS

Orateur

Ann Almgren (Lawrence Berkeley Lab, USA)

Description

Computational astrophysics has traditionally relied on discretizations of either the fully compressible equations for fluid dynamics, or the anelastic approximation, supplemented by equations describing the thermonuclear reactions and heat release. The low Mach number formulation, like the anelastic approximation, analytically removes acoustic wave propagation from the system. However, the more general low Mach number approach retains nonlinear compressibility effects resulting from nuclear burning, compositional changes and changing radial stratification. This model is a generalization of the pseudo-incompressible approximation to systems with a non-ideal gas equation of state and a time-varying base state. I will discuss the derivation of the low Mach number equation set for astrophysics, focusing on the similarities with and differences from numerical models of the Earth's atmosphere.

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