Testing of Paraffin-based Hybrid Rocket Fuel using Gaseous Oxygen Oxidiser

A series of paraffin-based hybrid rocket fuel has been studied experimentally in a laboratory-scale motor. To enhance the regression rate of paraffin solid fuel, three types of grain configurations: Cylindrical, star, and helical grain configurations of paraffin wax have been developed and tested with gaseous oxygen. The helical fuel grain presented best performance among all the test ports. About 40.2 per cent and 20.6 per cent regression rates are increased by burning paraffin fuel with helical and star grain configuration respectively, as compared to cylindrical grain configuration at Gox=0.0191 g/mm2s. The regression rates were significantly influenced by the oxygen injection pressure varied between 344.7 kPa and 620.5 kPa. Furthermore, the experimentally obtained exponents of oxidizer mass flux for all three grain configurations have been found to be significantly different from those of the classical hybrid system. Finally, thrust-time traces for all three grain configurations were also studied. The result shown no significant increase or decrease in the amplitude of the thrust oscillations.Defence Science Journal, 2012, 62(5), pp.277-283, DOI:http://dx.doi.org/10.14429/dsj.62.234