Design methods of two-phase axial plug nozzle

This paper proposes an improved Angelino method and an improved 'Parabola plus Cubic' curve method to design the solid-propellant axial plug nozzle on the assumption of constant velocity drag coefficient for two-phase flow. The performances of the two-phase plug nozzles designed by the improved methods are computed. The examples in the paper indicate that the length of rhe plug contour designed by the improved Angelino method is cut down by about 33%, and the thrust is increased by about 1%, comparing to the plug contour without considering the two-phase factors. The length of the one designed by the improved 'Parabola plus Cubic' curve method is cut down by about 6%, and the thrust is increased by about 4%.