转速-功率耦合摩擦通断式负载对涡扇发动机性能影响研究

Effects of rotational speed-power coupling friction on-off load on turbofan engine performance

关键词:  涡扇发动机  低压轴功率提取  离合装置  仿真分析  试验

Key words:  Turbofan engine  Extracting power from low-pressure spool  Clutch device  Simulation analysis  Experiment

摘要:

针对传统航空发动机采用的高压轴功率提取方式容错能力低且功率输出能力不足，以及负载装置长时间运转等问题，提出了一种带离合装置的涡扇发动机低压轴功率提取方案，建立了系统耦合模型，搭建了整机试验系统并提出了试验方法。采用数值计算和试验验证相结合的方法，研究了转速-功率耦合摩擦通断式负载对涡扇发动机性能的影响。研究结果表明：涡扇发动机低压轴具备大功率提取能力，且发动机低压轴带负载起动、高低压轴大转速差运转等技术路径可行，但存在排气超温和压缩部件稳定裕度下降问题；降低负载功率、延长作动时间、选取适合的压紧力值并考虑安全裕度1.5、在发动机低状态作动等措施，有利于发动机在离合装置作动过程的安全运转；建立的系统耦合模型具有良好的仿真精度，稳态和动态计算误差均小于6%；试验方法合理有效，试验验证过程中各参数良好，可为其他类似相关试验提供参考。

Abstract:

Aiming at the problems such as low fault tolerance and insufficient power output capacity of the high pressure shaft power extraction method adopted by the traditional aero-engine， as well as the long time operation of the load device， a low pressure shaft power extraction scheme of turbofan engine with clutch device was proposed， the system coupling model was established， the whole machine test system was built and the test method was proposed. The effects of rotational speed-power coupling friction on-off load on turbofan engine performance were studied by numerical calculation and experimental verification. The results show that the low-pressure shaft of turbofan engine has the ability of high-power extraction， and the technical paths of the low-pressure shaft starting with load and running with the larger high and low pressure shaft rotational speed difference are feasible， but there are problems such as exhaust over temperature and decreasing stability margin of compression components. Taking measures such as reducing the load power， prolonging the actuation time， selecting the appropriate compression force value and considering the safety margin of 1.5， and actuating in the low state of the engine are beneficial to the safe operation of the engine during the actuation of the clutch device. The established system coupling model has good simulation accuracy， and the steady-state and dynamic calculation errors are less than 6%. The test method is reasonable and effective， and the parameters in the process of test verification are good， which can provide reference for other similar experiments.