航空发动机内部容腔耦合响应规律

In order to accurately evaluate volume packing effects of aero-engine in rapid transients, a low-dimensional modeling method and the corresponding governing equations for the aero-engine internal cavities were proposed. By means of integrating the coupling algorithm of aero-engine main gas path and secondary air-system, an aero-engine whole gas path model considering volume packing effects was established. Predictions and analysis were made for the cavities responses in aero engine system environment during rapid transients. The result showed that the volume packing effects exerted little effects on the overall transient performance of the aero-engine, but its effect can cause significant imbalanced local responses in aero-engine gas path. In the process of rapid engine maneuvering, the relative change amplitude of the peak axial force can reach about 10% of the design value of the axial force, which increased the potential safety risk in the transition process of the aero-engine. And when the cavity characteristic time was less than 0.01 s, the effect of its volumetric effect on the aero engine can be basically ignored. The closer the characteristic time of the cavity was to the thrust response time of the engine, the higher the risk of dangerous transition state loads, making it an influencing factor that should not be ignored in modern high-performance aero-engine designs.