Modeling of thermonuclear fusion flames : transition to detonation

TL;DR

This paper investigates the mechanisms behind the transition from deflagration to detonation in stellar media, focusing on thermal runaway caused by feedback between flames and precompression, using a one-dimensional flame-folding model.

Contribution

It extends previous work by modeling more realistic fuel-fuel kinetics and demonstrates that thermal runaway persists under these conditions.

Findings

Transition occurs before flame merges with precursor shock.

Runaway effect persists with fuel+fuel kinetics.

Transition does not reach Chapman-Jouguet deflagration threshold.

Abstract

The paper is concerned with identification of the key mechanisms controlling deflagration-to-detonation transition in stellar medium. The issue of thermal runaway triggered by positive feedback between the advancing flame and the flame-driven precompression is discussed in the framework of a one-dimensional flame-folding model. The paper is an extension of the authors' previous study dealing with the non-stoichiometric fusion, $fuel \to products$, kinetics (Phys.Rev.E, 103(2021)) over physically more relevant, $fuel+fuel \to products$, kinetics. Despite this change the runaway effect endures. The transition occurs prior to merging of the flame with the flame-supported precursor shock, i.e. the pretransition flame does not reach the threshold of Chapman-Jouguet deflagration.