Abstract
Low specific speed Wedge type impellers with high performance are developed, which impellers are applied to high-pressure multistage compressors. Conventional low specific speed impellers have thin blades and small blade heights.Therefore, efficiency of low specific speed impellers is lower than that of high specific speed impellers, because the large wetted perimeter causes large skin friction loss. Wedge type impellers with thick blades and large blade heights are examined to reduce the skin friction loss. Designed Wedge type impellers were fabricated and tested. Results show that in case of Wedge type impeller the normalized stage efficiency increases by 6% and operating flow range expands significantly as compared with those of the conventional 2D impeller stage.
