Performance Analysis of Paraffin Fuels for Hybrid Rocket Engines

Abstract

The paraffin-based fuel has high regression rate and power, which is an ideal energy source for hybrid rocket engine. The research findings showed that: the energy characteristics of paraffin fuel and HTPB fuel with different oxidizers are similar; the specific impulse of paraffin fuel and HTPB fuel with LOx is the highest about 3194.3 N·s/kg and 3259 N·s/kg, respectively; the paraffin-based fuel/LOx propellant has low optimum oxygen to fuel ratio and high specific impulse, which is suitable for large hybrid rocket engine; the decomposition temperature of pretreated paraffin is higher than that of the unprocessed paraffin, but lower than that of HTPB; the chemical kinetics parameters of pretreated paraffin-based fuel has been calculated in oxygen atmosphere, and “E” is 101.72 KJ/mol, and pre-exponential factor “A” is 4.53382 × 1011; the melting characteristics of paraffin-based fuel and HTPB fuel have been verified by the solid fuel melting experiment; the regression rate of paraffin-based fuel is higher than the common HTPB fuel under the same conditions; with the increase of oxidizer mass flow rate, the regression rate of solid fuel increases accordingly for the same fuel formulation; the vortex formation occurs at the front section of the hybrid engine and the afterburner section in the numerical simulation, while the main exothermic reactions take place at the section above the fuel surface and after burning chamber.