Some observations of the controlled generation and onset of detonation

Abstract.

Detailed observation of deflagration to detonation transition (DDT) is inherently difficult. This is primarily due to the stochastic nature of flame acceleration and shock formation processes that in most practical situations give rise to the conditions required for detonation to emerge. The present paper describes how shock tube techniques have been used to control the conditions required for the onset of detonation. The paper first outlines some initial experiments involving turbulent flame acceleration before concentrating on experiments in a reflected shock mode. To aid interpretation of the observations the paper also presents a simple gasdynamic analysis of particle trajectories and considers the various physical and chemical processes that could lead to the onset of detonation.