Behaviour of the Leg of the Horseshoe Vortex Around the Idealized Blade With Zero Attack Angle by Triple Hot-Wire Measurements

Abstract

The paper presents the flow measurements within the leg portion of the horseshoe vortex. An uncambered blade of constant thickness downstream with a half-circular nose of an idealized turbine blade was installed on a flat plate. The six components of the Reynolds stresses were measured in addition to the three mean velocity components at two cross-sectional planes by a triple wire probe. The predominant vortical motion of the secondary flow occurs at the corner of the blade and the endwall. The effect of the penetrative motion of the free-stream toward the corner region induced by the vortex on the Reynolds stress is found in u2 profiles near the blade, but not in v2 profiles. The diffusion of the Reynolds stresses is observed in the crossflow direction.