Experimental determination of PE regression rate with an axial GOX injection

In this paper, a hybrid motor performance with high density poly ethylene (HDPE) as fuel and gaseous oxygen (GOX) as oxidizer was studied. Oxidizer was injected into nozzle with an axial injector. Effect of parameters such as mass flux, combustion chamber pressure, and distance from grain lead were studied through tests and by means of data reduction techniques. Besides, effect of utilizing pre-combustion chamber was studied. It was shown that using pre-combustion chamber helps to have an even regression in axial direction. In this case, regression rate was independent from axial location from grain lead. Dependency of regression rate to combustion chamber pressure was also determined which showed a good agreement with available empirical data. Finally, a classic regression rate relation for poly ethylene was determined in terms of total mass flux and combustion chamber pressure.