Study Of Cascade And Multi-Stage For High-loaded Helium Compressor

As the big difference of physics properties between helium and air, helium compressor hasspecial aerodynamic performance. And this compressor which is designed by traditional guide-line usually has low stage pressure ratio and excessive stages. Increasing stage load and stagepressure ratio is a trend for the problem. The performance of cascades and multi-stage of thehigh-loaded helium compressor were studied using the commercial CFD package by NUMECAInc.810schemes composed of five parameters combination on cascades were simulated underthree different incidence angles （0°,-2°,-4°）. Associated study was performed on the results.And the difference between actual angle of attack and theoretical angle of attack was also underconsideration.Aerodynamic design and simulation of single stage under high load condition was con-ducted by means of three-dimension blade formative program which was suitable for heliumcompressor based on the results of cascade. Study compared with conventional design was alsocarried out. Results showed that the scheme of high-loaded cascade stacking tothree-dimensional stage was reasonable. The stage pressure ratio and the load of high-loadedscheme were much higher than the conventional condition, and the efficiency maintained a highlevel.Six-stage high-loaded helium compressor was designed based on the study above, andperformance of design condition and off-design condition were also studied. Results showedthat the total pressure ratio ran up to1.9965with an average stage pressure ratio of1.122, theefficiency was86.55%. Besides, study of off-design performance showed that the six-stage he-lium compressor under consideration had certain stable operating range.