重复使用液体火箭发动机涡轮泵安全寿命预估方法

Based on the life distribution model of complex system and fault tree analysis (FTA) theory, a safety life prediction method of turbopump was established.As an example, the safety life of the high pressure liquid hydrogen turbopump (HPFTP) of the space shuttle main engine (SSME) was verified to demonstrate this method.The results showed that:(1) The life of complex system roughly followed the exponential distribution when the number of HPFTP critical components was more than 10, and a more reliable result accompanied a larger number.(2) The mean time between failure (MTBF) and mean time to repairment (MTTR)of HPFTP was 76 917 h and 8 879 h, respectively, and the safety life of 0.998 8 reliability was 25 575 s, which can be used 49 times safely;the safety life of 0.999 6 reliability was 8 521 s, which can be used for 16 times;the reliability was 0.999 7 for 11 times safety use.(3) The key components of HPFTP safety life were turbine blade and nozzle, and their corresponding critical importance was 0.217 5 and 0.216 6, respectively, and the critical importance of both liquid collector and the impeller was 0.174 2.This work can provide a reference for the reusability research of complex components such as liquid rocket engine turbopump.