The variation in strength of transverse shocks in detonation waves

Interferograms of detonation fronts, with a single Mach stem interaction in each principal plane orthogonal to the front, have been used to determine the variation of strength of the transverse shock along its length. As the transverse shock interacts with the reactive flow field behind the incident shock, both its strength and inclination vary with distance downstream. From the observed density profile and the reaction kinetics of the system, values of the density ratio across the transverse shock are computed. The predicted particle velocity profile behind the front confirms that a one-dimensional approximation is valid in the region of interest close to the front, and also that the calculated values are compatible with the Chapman-Jouguet (CJ) theory at a distance further downstream. The theoretically derived transverse wave velocity is taken to be the measured quasi-steady value of 1.2 a_CJ, where a_CJ is the equilibrium CJ sound speed.