John B. Bell
Lawrence Berkeley National Laboratory
Low Mach number simulation of nuclear flames in type 1A supernovae
Abstract: The early stages of a type Ia supernova are characterized by deflagration waves that propagate at a small fraction of the Mach number. In this talk, we will introduce a numerical model for the simulation of these nuclear flames in Type Ia supernovae based on a low Mach number formulation. The low Mach number formulation analytically removes acoustic wave propagation while retaining the compressibility effects resulting from nuclear burning. This formulation generalizes low Mach number models used in combustion that are based on an ideal gas approximation to arbitrary equations of state such as those describing the degenerate matter found in stellar material. The low Mach number formulation permits time steps that are controlled by the advective time scales resulting in a substantial improvement in computational efficiency compared to a compressible formulation. We will briefly discuss the basic discretization methodology for the low Mach number equations and their implementation in an adaptive projection framework. Computational results demonstrating enchancements to the flame speed resulting from Landau-Darrieus and Rayleigh-Taylor instabilities will be presented.| Zeit: | Freitag, 05. November 2004, 16.15 Uhr (Kaffee/Tee um 15.30) |
| Ort: | FU Berlin, Arnimallee 2-6, Raum 032 im EG |