可调扩压器端隙控制对离心压气机性能影响

The variable geometry compressor (VGC) driven by the high speed electric motor can match the air supply requirements of the airplane cabin within the whole flight envelop. Meanwhile, it can enable the compressor to work in high efficiency region and decrease the power consumption of the cabin pressurization system. The clearances between the vane tips and diffuser walls are necessary for the variable vane diffuser to operate. Because of the small height of the diffuser vane, the vane clearance-to-height ratio is relatively large and leads to strong side clearance leakage loss, which brings significant negative influence on the compressor performances. In order to suppress the side-gap leakage flow in the variable vane diffuser and improve the compressor efficiency, the influence of the diffuser side-gap leakage on the compressor performance was investigated and a pedestal-mounted variable vane structure was developed. By alternating the flow path of the sidegap leakage flow, the benefits of the new vane structure on the side-gap leakage suppression and compressor performance improvement were investigated. Results indicate that the new variable diffuser can effectively suppress the side-gap clearance leakage loss and improve the efficiency of the VGC compared to the traditional full side-gap VGC. For the VGC investigated in current study, the peak efficiency was increased by 1.1% and the corresponding pressure ratio was increased by 1.3%.