补燃循环上面级发动机初始驱动参数选取

Selection of initial driving parameters for upper stage engine with staged combustion cycle

某补燃循环上面级发动机是我国首台采用起旋氧预压涡轮泵起动方式的液体火箭发动机,其在起动初始阶段的能量匹配过程与现有型号存在较大差异。为使其获得良好的起动性能,需要对该发动机的初始驱动参数进行设计与分析。根据系统特点建立补燃循环上面级发动机起动过程的数学模型,基于MWorks软件,通过数值仿真手段设计初始的起动参数。最后按照设计的参数,对二级泵后煤油的接力能力进行评估。结果表明:预压涡轮氦气驱动流量应选为17.5 g/s,点火剂供应路节流圈流阻系数应选为7.95×10^(12)m^(-4);设计的起动参数能够使二级泵后煤油正常接力,且余量充足。

An upper stage engine with staged combustion cycle is the first liquid rocket engine in China that adopts the pre-booster turbopump start-up method,and its energy match process during the initial stage of start-up is different from the existing models.In order to obtain excellent start-up performance,it is necessary to design and analyze the initial driving parameters.The mathematical model of the engine start-up was developed according to the system characteristics,and the initial driving parameters were designed by the numerical simulation of MWorks software.Finally,the relay capacity of the kerosene after the secondary fuel pump was evaluated according to the designed parameters.The results show that the driving flow rate of pre-booster turbine should be selected as 17.5 g/s,and the flow resistance coefficient should be selected as 7.95×10^(12)m^(-4)for the throttle ring of igniter supply circuit.The designed driving parameters can make the kerosene normal relay after the two-stage pump,and its margin is sufficient.