모터 구동 고속 원심압축기의 성능과 공역학적 불안정성에 대한 실험적 연구

The performance and the instability of a motor-driven high-speed centrifugal compressor supported by air bump bearings were investigated experimentally. The test compressor has two single stages with two centrifugal impellers installed at the both ends of the motor shaft respectively. The performance test for each stage of the compressor was conducted with the variation of flow rate and impeller rotating speed. In order to investigate the unstable characteristics, unsteady pressure fluctuations with flow rate and rotor rotating speed were measured by using high frequency pressure transducers mounted on the shroud casing wall. From the measurement results, the aerodynamic instability of the compressor system was discussed in detail.