一种针对液体火箭发动机可靠性的双线评估方法

针对液体火箭发动机可靠性评估过程中试验数据利用不充分、主观性强、与设计改进关联不足等现状,给出了一种可靠性双线评估方法,在有限试车条件下提升可靠性评估结果的准确性,并从风险控制角度识别出发动机的薄弱环节.该方法采用两条主线开展可靠性评估,第一条线以发动机部组件试验数据为输入,以发动机工作时序为线索,识别发动机故障模式,...

A Two-line Assessment Method on Reliability of Liquid Rocket Engines

Aiming at the problems in the reliability assessment of Liquid Rocket Engine, such as insufficient utilization of test data, strong subjectivity, and insufficient correlation with design improvements, a two-line assessment method on reliability was presented to improve the accuracy of reliability assessment results under limited test information. In addition, the weak links of Engine could be identified from the perspective of risk control. This method used two main lines for reliability assessment. Firstly, taking the engine component test data as input, a reliability model was established based on the engine working sequence and Engine failure mode, and the probability of component failure was brought into the reliability model to obtain the prior information of engine reliability using uncertainty propagation method. Then, the engine test data was used to obtain the sample information of engine whose life times was considered to follow a Weibull distribution. Subsequently, the Bayesian method was used for information fusion to calculate the posterior distribution of engine reliability. This method expands the amount of data for reliability assessment, identifies the key component failures of the engine from a risk control perspective, and improves the engineering application value of reliability assessment.