Relation between Power and Energy in the Shock Initiation of Detonations. I. Basic Theoretical Considerations and the Effects of Geometry

摘要

Recent studies on the direct initiation of gaseous detonations have shown that initiation depends not only on the energy deposited but also on the rate at which it is deposited, namely the power. In this paper, we have used a theoretical model to determine the relation between the power and the energy required for the initiation of planar, cylindrical and spherical detonations in a detonable gas mixture. The results from the model show that the qualitative differences in the power-energy relations obtained from two different experimental arrangements are due to differences in the geometry. We also show that the minimum power requirement corresponds to a shock of the minimum. Mach number only in the case of planar detonations. Finally, the effect on the power-energy relation of the ratio of specific heats and the experimental uncertainties in the determination of the induction times have been studied for an acetylene-oxygen-nitrogen mixture. (Author)