Theoretical Analysis on Deflagration-to-Detonation Transition

TL;DR

This paper provides a theoretical analysis of the deflagration-to-detonation transition (DDT), establishing a critical velocity condition at about 60% of the Chapman-Jouguet detonation speed, which triggers detonation.

Contribution

It introduces a concise theoretical expression for the critical condition of DDT, linking it to a specific deflagration wave velocity threshold.

Findings

Critical deflagration velocity is about 60% of C-J detonation speed.

When this velocity is reached, detonation is immediately triggered.

The critical velocity is nearly equal to the sound speed of combustion products.

Abstract

The study on deflagration-to-detonation transition (DDT) is very important because this mechanism has relevance to safety issues in industries, where combustible premixed gases are in general use. However, the quantitative prediction of DDT is one of the major unsolved problems in combustion and detonation theory to date. In this paper, the DDT process is studied theoretically and the critical condition is given by a concise theoretical expression. The results show that a deflagration wave propagating with about 60% Chapman-Jouguet (C-J) detonation velocity is a critical condition. This velocity is the maximum propagating velocity of a deflagration wave and almost equal to the sound speed of combustion products. When this critical conation is reached, a C-J detonation is triggered immediately. This is the quantitative criteria of the DDT process.