Research on three-dimensional blade designs in an ultra-highly loaded low-speed axial compressor stage: Design and numerical investigations

To realize whether the rules for controlling the blade three-dimensional stacking line in a compressor with conventional loading level could be used for the design of a highly loaded compressor, the effects of three-dimensional bladings in an ultra-highly loaded compressor stage were studied numerically. A low-speed compressor stage (Stage-C) with ultra-high loading coefficient (=0.52) was designed at first. Due to the well-chosen through-flow design parameters accompanied using controlled diffusion airfoil with spikeless leading edge, Stage-C achieved the design goal of loading level with high peak efficiency of about 0.89. However, all the blades in Stage-C were designed with radial stacking lines. And then, Stage-C-three-dimensional was re-designed with non-radial stacking blades based on Stage-C, after which 1-point compressor efficiency profit was achieved. Based on the numerical simulations, the performance change in the two compressors and also the effects of blade three-dimensional stacking were discussed in depth. It was found that the endwall corner separation and secondary flows could be suppressed effectively using endwall bending; however, the blade forward sweep design at the rotor tip failed due to strong rotor-stator coupling effects in the highly loaded compressor stage.