Flame response of solid laminate propellant AP/HTPB to pressure perturbations

The experimental work presented in this paper deals with the flame response of a solid laminate propellant AP/HTPB to pressure perturbations. Experiments were performed in closed tube pressurized under 1MPa. The pressure perturbations are created by a pulser system connected to the end of the combustion chamber. The combustion process of a three layers of AP/HTPB was recorded by using a microscope and a high speed camera. The qualitative analysis of the flame images of the two cases, with and without pressure fluctuations, revealed that the standing acoustic waves established in the tube has strongly affected the flame and the combustion products flow. The flame response was translated by an oscillation motion above the burning surface. Thus, the burning surface profile was changed which means that the regression rate value may fluctuate.