Comparative analysis regarding burning process for different fuels in hybrid rocket engines

Hybrid rocket engines represent a propulsion system which at the moment needs to be improved by two ways: NOx and CO pollutant reduction together with safety and cost issues. In present paper there is represented a comparison between different fuels upon the combustion parameters. For this purpose there are assumed different input values from experimental tests. Presented case it is a necessary step to achieve improvements in hybrid rocket engines design and development, starting from the analysis of regression rates for different fuels like HTPB, paraffin, HTPB+AL, PE Wax. Early versions of hybrid rockets were not used at large scale either for commercial or military domain, main reason is that they had a slow fuel regression rate and a reduced combustion efficiency. To increase the regression rates it is necessary to increase the flow rate of pyrolyzed fuel, this way also increasing the thrust level. At the actual stage, the regression rate for the fuels based on polymers are higher than the conventional fuel used in hybrid rocket engines.