关键词: 液体火箭发动机;脉冲推力器;脉动燃烧;排气

Abstract: By using a moving injector,the combustion chamber pressure of pulse thruster may be much higher than feed system supply pressure.In order to analyze the characteristics of pulse thruster,a mathematical model for extrusion and exhaust process of monopropellant engine was developed.Using Hydroxyl Ammonium Nitrate(HAN)-based monopropellant as an example,the equation sets were calculated with fourth-degree Runge-Kutta method.According to calculating results,the maximal pressure as well as average pressure of combustion chamber are higher than supply pressure,on account of the approximate constant-volume combustion.The performance difference between pulse thruster and conventional constant-pressure thruster was compared.Results show that,under the same mean thrust and area ratio,the specific impulse of pulse thruster has increased 5 s,whereas,the throat area reduces 89%.If the exit area of nozzle is equal,the specific impulse of pulse thruster would increase 31.5%.

Key words: Liquid propellant rocket engine;Pulse thruster+;Pulse combustion;Exhaust gas