Turbulence-Flame Interaction on the Early Evolution of Flames in Type Ia Supernovae
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Date
2011
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Abstract
Description
Type Ia supernovae are bright stellar explosions thought to occur when a runaway thermonuclear
reaction incinerates a compact star known as white dwarf (WD). In many models, the explosion
begins with a flame born in the turbulent environment near the center of the white dwarf. The
effect of turbulence on the evolution of the nascent flame is incompletely understood and is the
subject of active research. The range of length scales from the full star (∼ 108 cm) to the laminar flame width (∼ 10−5 cm) prevents full-star simulations from resolving the turbulence-flame interaction (TFI) directly. In the single-degenerate paradigm of Type Ia supernovae (SNe Ia), the WD experiences ∼ 1000 year period of convection as the temperature rises to burn carbon. When the nuclear burning timescale exceeds the turnover time for convective eddies, a flame is born in the center of a vigorous convection field (vrms ∼ 400 km/s) extending out to enclose ∼ 70% of the WD’s mass [1]. We present preliminary results from a physically-motivated TFI model inspired
by Colin et al. (2000) [2] that utilizes a local, instantaneous measure of the turbulence to enhance
the flame speed due to under-resolved TFI. We explore various implementation choices in the
TFI model and compare results to previous work. We present two simulations of the early flame
evolution in a supernova. One incorporates a TFI model with particular implementation choices,
while the other relies only on indirect buoyancy effects [3].
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Citation
Jackson, A., Calder, A., Townsley, D., Chamulak, D., Brown, E., Timmes, F. (2011):
Turbulence-Flame Interaction on the Early Evolution of Flames in Type Ia Supernovae,
11TH Symposium on Nuclei in the Cosmos (NIC XI), vol. 100.