CHANGE IN SHOCK-WAVE PRESSURE IMPULSE WITH DISTANCE NEAR THE SOURCE.

One of the quantities that characterizes the destructive action of an explosive source is the shock-wave pressure impulse, which is defined as the integral over time of the pressure disturbance in the compression phase of the explosion wave. Change in shock-wave impulse affects the behavior of the low frequency portion of the spectrum. The author tries to bring more clarity in interpretation of the slow decay of shock wave pressure impulse with distance and the influence of nonlinear effects on the shock wave front. The same phenomena has also been observed for an explosion in air. Since such behavior of the impulse is caused by the existence of a flow of the medium behind the shock front, it is evident that with increase in mass of the detonation products and with increase in their expansion rate the effect of retarded falloff of shock-wave pressure impulse will appear more markedly.