Lacking of fault samples is a knotty problem in the fault detection of complex systems such as Liquid-propellant Rocket Engines (LRE).
在对类似于液体火箭发动机这种复杂系统的故障检测过程中，一个非常棘手的问题是缺乏故障类样本。
2
Liquidpropellant combustion processes are quite complicated and defy precise analytical description.
液体推进剂燃烧过程是相当复杂的，很难对其进行严谨的分析描述。
3
This paper attempts to analyse the tendency to develop liquidpropellant rocket propulsion technology according to the requirements o launch vehicles and spacecrafts.