Regression Rate Study of PVC/HTPB Hybrid Rocket Fuels

In the present study an effort is made to investigate the local regression rate, average regression rate through the effect of oxidizer injection pressure. For experimental investigation a lab scale ballistic test motor is designed and number of static test firing are carried out at different gaseous oxidizer injection pressure. The injection pressure is varied from 150psi to 420psi and a Swirl Injector and a conventional Shower Head Injector are used for the oxidizer injection from oxidizer chamber to fuel grain port. The local regression rate is obtained from the unburnt fuel web thickness after 10.5 second of test firing. Further, the investigation of regression rate of PVC and HTPB solid fuels are depended on mass flux of oxidizer as the regression rate shown a decreasing trend from head end to nozzle end. From the present analysis, it can be summarized that for PVC solid fuel regression rate is completely dependent on swirl injection of oxidizer, as well as the oxidizer injection pressure. Keywords-Regression rate,mass flux,HTPB,PVC ;