涡轴发动机性能非确定性模型校核与应用

Verification of Turbo-Shaft Engine Performance Uncertainty Model and Applications

关键词:  涡轴发动机  性能  非确定性  循环参数  裕度设计

Key words:  Turbo-shaft engine  Performance  Uncertainty  Cycle parameters  Margin design

摘要:

为了使涡轴发动机性能非确定性模型能够在工程中应用，利用均值法和发动机温度特性试验数据对其进行了校核，输出功率均方根误差为2.1%，耗油率为1%。基于此模型，对涡轴发动机循环参数选择和自由涡轮效率裕度进行了研究。结果显示，当考虑涡轮进口总温升高引起的涡轮冷气量变化及冷却气掺混引起的涡轮效率变化时，现有循环参数选择范围已不能满足发动机性能指标要求。根据控制燃气发生器的相对转速保持为设定值不变的控制方案，当自由涡轮效率裕度提高1.8%时，发动机输出功率和耗油率达标概率≥95%。

Abstract:

In order to make the turbo-shaft engine performance uncertainty model utilized in engineering design，using the average verification method，the turbo-shaft engine performance uncertainty model is verified with the engine performance temperature characteristics test data，and the output power verification root mean square error is 2.1%，the SFC is 1%. Next，the selection of cycle parameters of a new turbo-shaft engine and free turbine efficiency margin design are carried out based on the verified model. Results show that，the current ranges of engine cycle parameters and levels of component performance cannot satisfy the requirements of engine performance targets once the change of turbine stage efficiency generated by the cooling air mixing with the main gas stream and the change of turbine cooling flow caused by the increase of the total turbine inlet temperature are considered. Under the first control scheme which the relative speed of the gas generator is kept on a certain constant value，the free turbine efficiency margin increases 1.8%，the probabilities of success of output work and SFC can exceed 95% together.