Low Mach Number Modeling of Type Ia Supernovae

Journal Article · Fri Aug 05 04:00:00 EDT 2005 · Astrophysical Journal

OSTI ID:877678

Almgren, Ann S; Bell, John B; Rendleman, Charles A; Zingale, Michael

We introduce a low Mach number equation set for the large-scale numerical simulation of carbon-oxygen white dwarfs experiencing a thermonuclear deflagration. Since most of the interesting physics in a Type Ia supernova transpires at Mach numbers from 0.01 to 0.1, such an approach enables both a considerable increase in accuracy and savings in computer time compared with frequently used compressible codes. Our equation set is derived from the fully compressible equations using low Mach number asymptotics, but without any restriction on the size of perturbations in density or temperature. Comparisons with simulations that use the fully compressible equations validate the low Mach number model in regimes where both are applicable. Comparisons to simulations based on the more traditional an elastic approximation also demonstrate the agreement of these models in the regime for which the anelastic approximation is valid. For low Mach number flows with potentially finite amplitude variations in density and temperature, the low Mach number model overcomes the limitations of each of the more traditional models and can serve as the basis for an accurate and efficient simulation tool.

• Research Organization: Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director. Office of Science. Advanced ScientificComputing Research, Department of Energy Grant DE-FC02-01ER41176; National Aeronautics and Space Administration NAGW-5-12036
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 877678
• Report Number(s): LBNL--58673
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Vol. 637; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCURACY
AMPLITUDES
COMPUTERS
MACH NUMBER
PHYSICS
SIMULATION
SUPERNOVAE
supernovae white dwarfs hydrodynamics numericalmethods