Relation Between Cell-Size And Detonation Parameters In Overdriven Gaseous Detonations

An experimental study of the cellular structure of overdriven detonation waves which are caused by the transition process from deflagration to detonation has been conducted. The results, relating cell size and detonation parameters, are presented in this paper. For mixtures of 2H 2 + O 2 , 2H 2 + 5air, and 2H 2 + O 2 + 3Ar it has been found that the relation between the number of transverse cells in a square tube, N , and the detonation pressure P is approximately linear, and the slopes of the ( N , P P CJA ) lines are almost the same for different mixtures and initial pressures. A simple formula, therefore, was obtained to estimate overdriven detonation pressure from cell size. The dependence of cell size on detonation velocity was also observed experimentally and analysis of the results has shown that L ≅ constant. Therefore, the conclusion for CJ gaseous detonation is that this result can be used to predict overdriven cases.