Experimental Investigation of Flow Structure and Nusselt Number in a Low-Speed Linear Blade Passage With and Without Leading-Edge Fillets

Abstract

The potential of contouring the leading edge of a blade to control the development of the secondary flows in the blade passage and to reduce the thermal loading to the end wall is investigated experimentally. Fillets placed at the junctions of the leading edge and the end wall are used for contouring. Four different types of fillet profiles are tested in a low-speed linear cascade a Reynolds numbers of 233,000 based on the inlet velocity. Images of instantaneous smoke flow patterns show a smaller horseshoe vortex along the leading edge with the fillets. In the passage, the fillets cause the passage vortex to be located closer to the suction surface. Upstream of the throat, the normalized axial vorticity values for the passage vortex and the turbulence intensity levels are smaller with the fillets compared to the baseline. For the leading-edge fillet with a concave profile, the end-wall Nusselt number distributions show significant reductions compared to the baseline.