The effect of phosphorus chemistry on recombination losses in a supersonic nozzle

In previous articles, phosphine combustion products were shown to catalyze H + OH recombination in equilibrium relaxation experiments. In this work, calculations of heat release and specific impulse are reported for combustion products expanding at supersonic velocities in a nozzle. The calculations use a reaction set with 11 phosphorus-containing reactions. The addition of several percent by mass phosphine to hydrogen fuel substantially increases the heat release per unit fuel mass calculated for the nozzle. A gain in specific impulse is calculated for fuel-rich combustion of hydrogen fuel with phosphine added.