涡扇发动机全包线加速控制计划改进方法研究

Improvement Method of Turbofan Engine Full-Envelope Acceleration Control Schedule

关键词:  涡扇发动机  加速控制计划  相似换算  等温线  全包线

Key words:  Turbofan engine  Acceleration control schedule  Similarity conversion  Isotherm  Full envelope

摘要:

加速控制计划直接影响了发动机的响应速度以及运行安全。为了提高发动机响应能力，提出了一种基于等温度线的发动机全包线加速控制计划。分别针对稳态和动态过程开展相似换算误差分析，证明并验证了关键参数在等风扇进口温度时，具有较高相似换算精度的规律。基于此换算误差理论，提出全包线加速控制计划改进方法，该方法在不同等风扇进口温度下设计多条加速控制计划，再通过线性插值得到包线内不同等温线下的加速控制计划。结果表明，改进后的加速控制计划相比于传统单点优化得到的加速控制计划，发动机加速至最大转速的98%所需的时间缩短了7.2%，最大转速提升了1%，且风扇、压气机喘振裕度和涡轮前温度等均未超出限制值。因此，该方法相比于传统单点优化方法，既提升了在包线内获取的加速控制计划的精度，又确保了发动机在包线内安全稳定工作的前提下更好地发挥加速性能。

Abstract:

The acceleration control schedule directly affects the response speed and operation safety of the engine. In order to improve the engine responsiveness， a full envelope engine acceleration control plan based on isotherm was proposed. A similarity conversion error analysis was conducted for steady-state and dynamic processes， respectively， and it was proved and verified that the key parameters have higher accuracy on similarity conversion at the same fan inlet temperature. Based on this conversion error theory， an improved method of full envelope acceleration control schedule is proposed. This method designs multiple acceleration control schedules at different equal fan inlet temperatures， and then obtains the acceleration control schedules under different isotherms in the envelope by linear interpolation. The results show that the improved acceleration control schedule compared to the traditional single operating point optimization of the acceleration control schedule， the time required for the engine to accelerate to 98% of the maximum speed reduced by 7.2%， the maximum speed increased by 1%. The fan and compressor surge margin and pre turbine temperature did not exceed the limit. Therefore， compared with the traditional single operating point optimization method， this method not only improves the accuracy of the acceleration control schedule obtained in the envelope， but also ensures that the engine can have better acceleration performance under the premise of safe and stable operation of the envelope.