500t级液氧煤油补燃发动机起动过程仿真研究

Numerical simulation of start-up process for 500 t thrust LOX/kerosene staged combustion cycle rocket engine

500t级液氧煤油补燃发动机是我国首台采用双推力室方案、自身分级起动方式的重型液体火箭发动机。结合重型发动机特点建立了描述发动机起动过程的数学模型,通过数值仿真分析了影响发动机起动特性的主要因素,确定了发动机的起动方案。研究结果表明:液氧主阀和发生器燃料阀打开时差应确保发生器点火在氧头腔充满后进行;流量调节器的转初级起始时间应早于推力室建压时间;燃料节流阀转大流量应在发动机起动受控段进行。

500 t thrust LOX/kerosene staged combustion cycle engine is the first liquid propellant rocket engine with dual-thrust chamber system in China. The mathematical model of describing the start-up process of engine was developed based on the characteristics of the heavy-duty engine. The sensitive parameters affecting start-up characteristic of engine were analyzed by means of numerical simulation, so a reasonable start-up scheme of the engine was determined. The research results reveal that the gas generator （GG） should not ignite before the mixing head cavity of the GG has been filled with liquid oxygen, the ignition of the combustion chamber （CC） should lag behind the rise of the temperature of the GG, and the throttle valve should be released to the main passage after start-up of the engine is under control.