Computation of nozzle two-phase flow in a N₂O/HTPB hybrid rocket motor

Numerical solutions of full Navier-Stokes equations were obtained for a nozzle two-phase flow of the nitrous oxide (N₂O)/hydroxyl-terminated polybutadiene CHTPB) based fuels hybrid rocket motor. MacCormack decomposition scheme and B-L algebraic turbulence model and two-phase equilibrium flow model were used. The nozzle flow and performance under three oxidizer-to-fuel ratios and four nozzle types were calculated. Effect of oxidizer-to-fuel ratio and nozzle type on nozzle performance was analyzed from the two-phase and gas phase results. Vacuum specific impulse is bound up with oxidizer-to-fuel ratio. This paper will be useful for the hybrid rocket motor design.