畸变进气时涡扇发动机整机环境下压缩部件气动稳定性评定

Aerodynamic stability assessment for compression component running in turbofan engine with distorted flow

关键词:  涡轮风扇发动机  气动稳定性  压缩部件+  数学模型

Key words:  Turbofan engine  Aerodynamic stability  Compression component+  Mathematical model

摘要:

将基于部件匹配技术的涡扇发动机非设计点性能计算模型和基于李亚普诺夫稳定性理论的压缩部件气动稳定性评定模型有机地耦合,实现了发动机整机环境下的压缩部件气动稳定性评定,使得该模型成为一种实用的涡扇发动机压缩部件气动稳定性分析模型。以某型涡扇发动机为例,计算比较了畸变进气时发动机整机环境和单独部件评定时风扇和压气机稳定工作边界的异同,从计算结果可以看到,对于风扇,畸变进气条件下,无论在高转速,还是低转速时,同样的进口畸变度,发动机环境下风扇的稳定裕度损失比单独部件下风扇的稳定裕度损失都小,即在发动机环境下评定风扇稳定性时,风扇对进气温度畸变不敏感,而在单独部件环境下评定时,风扇对进气畸变比较敏感。对于压气机,进口气流存在压力畸变时,采用高压涡轮导向器变化对压气机逼喘过程中,风扇的共同工作线向喘振边界靠近,而进口气流存在温度畸变时,逼喘过程中,风扇的共同工作线基本不变。

Abstract:

A new model was presented for predicting aerodynamic stability limit of fan component in turbofan engine.Firstly,a quasi one-dimensional,time dependent compression system model was used to model the dynamic flow in compressor and the actuator-lag-volume model was adopted to model the stage of compressor.Secondly,lyapunov stability theory was used to identify the aerodynamic stability of compression component.Finally,this aerodynamic stability numerical model was coupled with steady state thermodynamic cycle model of turbofan for predicting aerodynamic stability limit of compression component in turbofan engine environment. A turbofan engine with 3 stages fan and 5 stages compressor,as an example,was simulated.Numerical results show that in different aerodynamic stability assessment environment the effect of inlet flow distortion on fan and compressor stability limit is different.