Theory of detonation initiation behind reflected shock waves.

An IBM 7094 digital computer program using the Method of Characteristics for nonsteady one-dimensional flow with heat addition has been developed to predict the properties of detonation initiation behind a reflected shock in hydrogen-oxygen-argon mixtures. It is postulated that the gas compressed by the reflected shock begins to react exothermically after a finite induction delay period. The locus of points at which this begins is assumed to form a reaction wave that travels through the reactive gas mixture with a velocity that is determined by both the motion of the initiating reflected shock and the kinetics. In addition, a reaction-shock is formed upstream of this because of heating in the exothermic region. The accelerations of the and reaction-shock waves are found to be coupled through a variable delay time that is dependent on the compressional heating history of each gas particle. The results obtained from the analysis agree with experimentally determined results in both qualitative and quantitative detail and therefore show that this type of detonation initiation represents a simple iiotisteady, one-dimensional coupling of gas dynamics and homogeneous chemical reaction.