Numerical investigation on subsonic axial-flow compressor rotor with implementation of axisymmetric casing contouring optimization

For the study object of a subsonic axial-flow compressor rotor of Northwestern Polytechnical University, a reliable numerical simulation method was presented, and then axisymmetric contouring optimization for the casing under the condition of peak efficiency was conducted with the module DESIGN/3D in software package NUMECA, and the optimal rotor was obtained finally. The optimal rotor pushed the tip clearance leakage vortex away from the suction side at the leading edge of the blade. Although this led to an increase of the magnitude of leakage vortex and flow loss at the first 30% axial chord, the magnitude of leakage vortex and flow loss were greatly reduced at the last 70% axial chord of the blade, thus reducing the total loss, and increasing the peak efficiency and absolute total pressure at the outlet. The efficiency of the optimal rotor increases about 0.36% under the peak efficiency condition, which increases more under large mass flow rate condition, but under the near stall condition, the optimal rotor forms low velocity zone earlier at the blade tip area, leading to an earlier stall and making the stability margin of the optimal rotor smaller.