Investigation on the Pulse Ⅱ Ignition Transient Operation Characteristics of Dual Pulse Motor

Abstract

In order to investigate the pulse Ⅱ ignition process of dual pulse motor,a mathematical physical simulation model was established based on Fluent software package. An user-defined function(UDF)was programmed to simulate the variable mass flow rate of ignition gases and the mass adding near the propellant surface due to the combustion. The transient flow-field characteristics before and after the rupture of compartment were analyzed. The results show that the pressure propagation velocity in the inner passage is faster than that in outer passage on the initial stage of ignition process. Before the rupture,the gas accumulates and propagates reversely,and the pressure in the tail increases faster than that in the head. After the rupture,shock wave exists because of the gas compressing the low-pressure gas,which results in severe flow field oscillation. The closer to the hole,the greater the pressure oscillation is.