A Unified Mechanism for Unconfined Deflagration-to-Detonation Transition in Terrestrial Chemical Systems and Type Ia Supernovae

TL;DR

This paper proposes a unified turbulence-induced mechanism for deflagration-to-detonation transition applicable to both chemical explosions and Type Ia supernovae, validated through experiments and simulations, with implications for supernova models.

Contribution

It introduces a unified theory of turbulence-induced DDT that explains detonation initiation in both chemical and thermonuclear explosions, particularly in supernovae.

Findings

DDT is almost inevitable at densities 10^7 - 10^8 g/cc in supernova models.

The theory is validated with chemical flame experiments and thermonuclear flame simulations.

Criteria for detonation initiation in supernovae are established.

Abstract

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 order to consume all of stellar material, but the mechanism for the deflagration-to-detonation transition (DDT) remains unclear. We present a unified theory of turbulence-induced DDT that describes the mechanism and conditions for initiating detonation both in unconfined chemical and thermonuclear explosions. The model is validated using experiments with chemical flames and numerical simulations of thermonuclear flames. We use the developed theory to determine criteria for detonation initiation in the single degenerate Chandrasekhar-mass SNIa model, and show that DDT is almost inevitable at densities 10^7 - 10^8 g/cc.