Design And Experiment On Main Charge Of Short Impulse Thruster

The short impulse thruster has simple structure and short action time, it is used forflight vehicle and trajectory control more and more widely. The overall structure and themain grain’s property are what determine the output performance of the short impulsethruster. In this paper, the main grain of the short impulse thruster has been designed on theprinciple of solid-rocket engine and concerning initiators and pyrotechnics. Forth more, theinfluencing factors of its output performance have been studied. The main contents of thedissertation are as follow.(1)Ammonium perchlorate and aluminate power that is called as NA are principalcomponents as one of the charge formulations, the other components are potassium picrateand hexogen，which is called KR in brief. The burning temperature，gas volume, powderpower and specific impulse were calculated with REAL computing program, which isbased on the principle of the minimum free energy method.(2)The combustion performance of the two kinds of main charge NA and KR wastested by explosion vessel experiment. The data from the test was used for analysis of therelationship of ignition time, combustion time, maximum pressure and different proportionmain grain formulations. According to experimental results an numerical simulation resultsby REAL，the optimum formulation was determined. Moreover, the powder power andspecific impulse were calculated by explosion vessel experiment results.(3)A kind of short impulse thruster was designed, constitute of ignition parts, airexhausting pipe, charging room and nozzle tube. Because of its’ charging outside,ventilating inside, the new structure could be increasing combustion-gas flowing time toguarantee the main charge stable combustion.(4)The influence of the different formulation of NA and KR，different powder chargeweights, different press pressures was evaluated, the results show that the charge NA needsgreater strength than NA and the KR’s property can change widely, the output impulse ofthe short impulse thruster grows with the weight of the main grain and the press pressure.