Miiftiobjective Optimization of Circumferential Casing Grooves for a Transonic Axial Compressor

摘要

RECENTLY, casing treatments using grooves or slots have been applied to axial compressors to prevent surge and enhance stall margin (SM). However, this is accompanied by a loss near the blade tip region, which leads to a decrease in efficiency of the axial compressor. Therefore, a systematic design of the casing treatment using multiobjective optimization techniques in conjunction with a flow analysis using three-dimensional Reynolds-averaged Navier-Stokes equations (RANS) was used to investigate a compromise between the SM and the efficiency of the compressor.Various types of grooves have been suggested by many researchers, and it has been reported that using grooves increases SM by delaying stall. Huang et al. [1] studied the effects of the configuration, width, and depth of circumferential groove casing treatment on SM by numerical analysis, and suggested that the stall mechanism was substantially influenced by tip clearance. Muller et al. [2] studied the effects of the number and depth of the grooves on SM by three-dimensional numerical analysis. Houghton and Day [3] examined the effect of grooves on rotor outflow blockage, and the near casing flowfield was studied using experimental and computational methods.