基于实验的发动机插板式进气畸变压力谐振分析

某型涡扇发动机插板式进气畸变实验中,当插板升高到35%以上,进气截面各个测点畸变扰动出现约为32 Hz大幅振荡.用气流压力波动方程计算了进气道容腔谐振频率为34 Hz.表明该谐振是由插板与发动机之间的容腔引起的.不同转速和流量下,计算和实验的结果都基本稳定.由分析可知:150 Hz以下脉动压力是大幅稳定和周期性的.高频部分主要是小幅随机压力脉动,其速率和加速度变化比较剧烈.在发动机喘振前,谐振频率压力振荡能量大大增加,其它低频和高频成分能量迅速减少,形成典型的谐振型压力振荡.

Test-based syntonic analysis of the aero-engine inserted-board inlet dynamic distortion pressure

Some observations from measuring the inserted-board airflow inlet distortion dynamic pressure field were presented in this paper.When the inserted-board rose above 35%,the inlet airflow disturbance occurred at about 32Hz.The pressure wave equation calculation shows that the Phase1 syntonic frequency is 34Hz.This syntony lies between the engine and inserted-board.Its frequency is steady at different rotor speeds and fluxes.The follow-on analysis indicates that the low frequency pulse pressure of component below 150Hz is powerful,steady and seasonal.The high frequency component is mainly stochastic pressure pulsation with minimum power.The changes of its rate and acceleration are great.When the engine is about to surge,the power of the syntonic frequency increases greatly while the power of other low frequency components and high frequency components decreases rapidly,so a typical syntonic pressure oscillation is formed.