抄録
Performance of the methane fueled rocket nozzles are numerically investigated using computational fluid dynamics approach. A simple set of chemical reactions and kinetics for methane/oxygen nozzle flow is proposed. The chamber pressure, mixture ratio and size of the nozzle are parametrically changed to study the influence of characteristic rocket engine design parameters on nozzle losses. The amount of dissociation is high when the chamber pressure is low and the kinetic loss becomes dominant compared to the other nozzle losses. The peak specific impulse is achieved at a higher mixture ratio region as the chamber pressure increases. The chemical non-equilibrium flow appears mainly at down stream region of the nozzle throat. The influence of the chemical non-equilibrium effect decreases as the chamber pressure increases. Supersonic chemically reactive gas stays longer in the nozzle as the size of the nozzle become larger and the amount of recombination increases which decreases the kinetic loss. When the chamber pressure is high, the kinetic loss becomes small and the effect of the size of nozzle also becomes small.
