Flow past a curved plate: Wake vortex characteristics

This paper presents the results of an experimental investigation on the wake vortex characteristicsof a curved plate (chord length, CL and diameter, D) with its convex face facing the flow at a Reynolds number value 5878 (based on CL). Flow-visualization experiments were conducted in a water channel which were video-recorded to carry out the frame-by-frame analysis of various cases. In this study, CL/D is varied from 0 to 1.0 by changing the radius of plate curvature keeping the chord length fixed; CL/D=0, 6/13, 3/4 and 1.0. For each case of CL/D, angle of flow incidence of the plate(α) is varied from 0° to 30° in steps of 5°. Three parameters were investigated in this study to deduce the effect of plate curvature and inclination, viz., vortex size (D
v
, average of the minor and major axes of the vortex since majority of the vortices are elliptical in shape), vortex length (L
v
, distance of the vortex tip from the plate leading edge) and Strouhal number (St). These parameters were estimated for both the upper vortices (shed from the upper shear layer) and lower vortices (shed from the lower shear layer). In engineering structures with similar geometries, these results carry significant practical relevance.