Experimental and Numerical Analysis of Hub-Corner Stall in Compressor Cascades

Abstract

The development of a corner stall has been investigated experimentally and numerically in a rotor hub equivalent compressor cascade operated at increasing loadings (inlet angles). The paper presents some of the experimental and numerical results, including midspan results, contour plots of the total pressure losses, pitchwise averaged total pressure losses and turning angles, flow visualization and, numerically only, visualization of so-called ribbons. These results have been analysed to finally identify an endwall separation vortex, increasing in pitchwise and spanwise direction with increasing loading in a highly complicated and permanently changing endwall topology, as the dominating feature of a developed corner stall.