Combustion in Thermonuclear Supernova Explosions

Modeling of thermonuclear fusion flames : transition to detonation

“…In dimensional units the parameter set (21) may correspond, e.g. to U p = 100km/s; a p = 10, 000km/s; T 0 = 2 • 10 9 K; T p = 10 11 K; T a = 9.1 • 10 15 ; ρ 0 = 5 • 10 9 g/cm 3 ; ρ 0 = 2.5 • 10 9 g/cm 3 , 4.25 • 10 9 g/cm 3 , which are quite realistic [1,7,15,20].…”

“…Unlike chemical ideal gas flames, Eqs. (3)-( 7) allow for a significant increase of temperature (T p ≫ T 0 ) under mild thermal expansion (ρ p ρ 0 ), typical of thermonuclear flames [1,7,15,20,21]. Despite this distinction, the positive feedback mechanism of ideal gas flames appears to hold also in thermonuclear flames.…”

“…Thermonuclear explosions of white-dwarf stars is a fundamental astrophysical issue, the first principle understanding of which is still commonly regarded as an open problem [1]. There is a general consensus that stellar explosions are manifestations of the deflagration-to-detonation transition of an outward propagating self-accelerating thermonuclear flame subjected to instability/ turbulence-induced corrugations.…”

Models for Type Ia Supernovae and Related Astrophysical Transients

“…Both deflagrations and detonations are subject to multidimensional hydrodynamic instabilities (for a recent review see Röpke 2017). While for the latter case, it is generally assumed that the effects on the overall explosion process are weak, deflagration burning is most likely dominatedand as a consequence significantly boosted -by the interaction with such instabilities.…”

“…On a wide sub-range of that turbulent cascade, the deflagration flame interacts with turbulent eddies (see Röpke andRöpke 2017 for discussions of turbulent deflagrations in SNe Ia). The effect of this interaction depends on whether turbulence corrugates the flame structure only on large scales, or whether it penetrates the internal flame structure and modifies the microphysical transport in it.…”