Influence of Wave Reflections on the Development of Detonation

One of the most significant features of the transition from deflagration to detonation is the dynamics of wave interactions occurring in the course of the process. Of particular interest is the effect of waves reflected from the closed end. The present study was based on a streak self-light photograph of a stoichiometric hydrogen-oxygen flame accelerating to detonation, and a simultaneous pressure transducer record taken at the closed end of the tube in the vicinity of the source of ignition. The photograph revealed considerable information on the flow field behind the flame, so that with the additional pressure measurement it was possible to deduce specific data on the changes of state in the gas, and the dynamic effects of wave reflections on the initiation of the process. The results were rationalized by means of a gas wave dynamic analysis yielding sufficiently complete wave diagrams of the phenomena to assess their importance with respect to the transition from deflagration to detonation.