重复使用液体火箭发动机结构可靠性分配

Allocation of structural reliability index for reusable liquid rocket engine

针对重复使用液体火箭发动机多次重复使用的特点,以发动机在重复使用全过程中各子系统的可靠性偏差最小为目标,提出面向重复使用全过程的重复使用液体火箭发动机结构可靠性分配方法。该方法以等可靠度分配为基础,以发动机在重复使用全过程中可靠性偏差为目标函数,采用遗传算法进行优化得到分配结果,可在满足发动机使用寿命末时刻可靠性的同时,减小各子系统在中间使用过程中"短板"效应。以某可重复使用氢氧发动机系统为例,给出了具体分配方法,相比于等可靠度分配法,所提出的分配方法得到的各子系统在发动机工作过程中的可靠度偏差下降35%,验证了该方法的有效性。

Aiming at the repeated characteristics and minimizing the reliability deviation of each subsystem during the whole service life,an allocation method of structural reliability index is proposed for the reusable liquid rocket engine.Based on the equal reliability allocation,this method takes the reliability deviation of whole service life as the objective function and uses the genetic algorithm to optimize the allocation results.It can avoid the“weak point”of each subsystem in operation while satisfying the reliability at the end of engine life.The specific allocation method is introduced with an example of reusable hydrogen-oxygen rocket engine.Compared with the equal allocation method,the reliability deviation of each subsystem in the whole engine service life is decreased by 35%,which validating the feasibility and effectiveness of proposed method.