Flow Study of a Redesigned High-Pressure-Ratio Centrifugal Compressor

A high specific speed, 6:1 total pressure ratio centrifugal compressor rotor has been improved with the knowledge gained from previous investigations on similar types of compressors and with the help of advanced 3D-design calculations. The new rotor has the same main dimensions as its predecessor and was designed for the same operating point. It was manufactured and was tested at DLR with conventional and optical measurement techniques. Performance and optical measurements were carried out up to tip speeds of 586 m/s. The investigations were supported by 3D stage calculations which delivered detailed insight into the impeller and diffuser flow development.