关键词: 对转压气机；进气畸变；临界畸变角；畸变指数；失速裕度

Abstract: This paper presents analysis of the circumferential total pressure distortion in a contra -rotating compressor(CRAC) by three dimensional steady full-passage numerical simulations，based on the validation of numerical results by experimental data. The critical distortion angle has been decided and the effects of different distortions on the performance curves and detailed flow structure have been analyzed with the focus of distortion spatial transfer in the CRAC. The results show that:(a)The critical distortion angle of the CARC is about 72°，which is a little larger than the traditional compressor(rotor and stator alternate arrangement).(b)The total pressure ratio and stall margin on the stall point have decreased by 3% and 9.6%，respectively，with distortion coefficient at 0.24 compared with uniform inlet condition. When the distortion coefficient is 0.5，the percentages are up to 8.3% and 19.8%，respectively.(c)The pressure gradient along the circumferential direction affects the relative velocity of the rotors distinctly，which plays different roles of the two counter rotating rotors. The incoming relative velocity and load of a rotor decrease when it enters into the distortion zone. On the other hand，the relative velocity and load increase when a rotor leaves the distortion zone.(d)The distortion level is amplified by the upstream rotor. The effect that the downstream reversed rotating rotor strengthens the mixing ability of flow，suppresses the development of distortion flow and then reduces the distortion level.

Key words: Contra-rotating compressor；Inlet distortion；Critical distortion angle；Distortion coefficient；Stall margin