相关论文: Can Deflagration-Detonation-Transitions occur in T…
We investigate the possibility of a delayed detonation in a type Ia supernova under the assumption that the transition to detonation is triggered by turbulence only. Our discussion is based on the Zeldovich mechanism and suggests that…
A promising model for normal Type Ia supernova (SN Ia) explosions are delayed detonations of Chandrasekhar-mass white dwarfs, in which the burning starts out as a subsonic deflagration and turns at a later phase of the explosion into a…
Although delayed detonation models of thermonuclear explosions of white dwarfs seem promising for reproducing Type Ia supernovae, the transition of the flame propagation mode from subsonic deflagration to supersonic detonation remains…
The delayed detonation model describes the observational properties of the majority of type Ia supernovae very well. Using numerical data from a three-dimensional deflagration model for type Ia supernovae, the intermittency of the turbulent…
Turbulent combustion is three-dimensional. Turbulence in a Type Ia supernova is driven on large scales by the buoyancy of burning products. The turbulent cascade penetrates down to very small scales, and makes the rate of deflagration…
Deflagration-to-detonation transition (DDT) can occur in environments ranging from experimental and industrial systems to astrophysical thermonuclear (type Ia) supernovae explosions. Substantial progress has been made in explaining the…
We study a type Ia supernova explosion using three-dimensional numerical simulations based on reactive fluid dynamics. We consider a delayed-detonation model that assumes a deflagration-to-detonation transition. In contrast to the pure…
Aims: We present the first full-star three-dimensional explosion simulations of thermonuclear supernovae including parameterized deflagration-to-detonation transitions that occur once the flame enters the distributed burning regime.…
The nature of type Ia supernovae (SNIa) - thermonuclear explosions of white dwarf stars - is an open question in astrophysics. Virtually all existing theoretical models of normal, bright SNIa require the explosion to produce a detonation in…
A simple, semi-analytic representation is developed for nuclear burning in Type Ia supernovae in the special case where turbulent eddies completely disrupt the flame. The speed and width of the ``distributed'' flame front are derived. For…
We derive the criteria for deflagration to detonation transition (DDT) in a Type Ia supernova. The theory is based on the two major assumptions: (i) detonation is triggered via the Zeldovich gradient mechanism inside a region of mixed fuel…
This paper outlines a theoretical approach for predicting the onset of detonation in unconfined turbulent flames which is relevant both to problems of terrestrial combustion and to thermonuclear burning in Type Ia supernovae. Two basic…
We study a Type Ia supernova explosion using large-scale three-dimensional numerical simulations based on reactive fluid dynamics with a simplified mechanism for nuclear reactions and energy release. The initial deflagration stage of the…
In the framework of the Chandrasekhar mass white dwarf model for Type Ia supernovae, various stages of the explosion are described in terms of the burning regimes of the thermonuclear flame front. In the early flamelet regime following the…
We examine the effects of turbulent intermittency on the deflagration to detonation transition (DDT) in Type Ia supernovae. The Zel'dovich mechanism for DDT requires the formation of a nearly isothermal region of mixed ash and fuel that is…
The nucleosynthetic characteristics of various explosion mechanisms of Type Ia supernovae (SNe Ia) is explored based on three two-dimensional explosion simulations representing extreme cases: a pure turbulent deflagration, a delayed…
Deflagration models poorly explain the observed diversity of SNIa. Current multidimensional simulations of SNIa predict a significant amount of, so far unobserved, carbon and oxygen moving at low velocities. It has been proposed that these…
The aim of this work is to characterize the thermodynamic state of fuel mixed into the turbulent flame brush in the context of the Zel'dovich deflagration-to-detonation transition (ZDDT) mechanism of Type Ia supernovae (SNe Ia). We perform…
We study a new mechanism for deflagration to detonation transition in thermonuclear supernovae (SNe Ia), based on the formation of shocks by amplification of sound waves in the steep density gradients of white dwarfs envelopes. Given a…
Type Ia supernovae are associated with thermonuclear explosions of white dwarf stars. Combustion processes convert material in nuclear reactions and release the energy required to explode the stars. At the same time, they produce the…