Base pressure model of plug nozzle

Base pressure model was analyzed and main factors influencing base pressure were found, i.e. pressure and Mach number at plug exit, plug exit angle and secondary mass flow rate. Then according to results of numerical computation and cold flow test data, three equations were summarized, which were the correlation among base pressure, pressure and Mach number at plug exit, the correlation between base pressure and plug exit angle, and the correlation between base pressure and secondary mass flow rate. At last, final equation was obtained, which was the geometric mean for three equations. It shows that the final equation can predict base pressure roughly as well as imply the way of base pressure variations with these factors.