The wake of a rectangular flat plate

Abstract The mean wake of a three-dimensional surface-mounted rectangular flat plate was studied experimentally in low-speed wind tunnel for four different aspect (height-to-width) ratios, AR = 3, 2, 1, and 0.5. Reynolds number based on the width Re 3.8 × 10 4 boundary layer thickness ground plane, relative to width, δ / W 1.1. incidence angle varied from α 0° (where is normal flow) 90° parallel flow). velocity vorticity fields were measured using seven-hole pressure probe. At 0°, length recirculation zone behind becomes progressively shorter as ratio lowered follows same tendency that finite square prism. wakes slenderer plates 3 2 are characterised by two pairs streamwise vortices: pair tip vortices upper ground-plane lower edges wake. With increasing angle, single vortex comes dominate wake, secondary induced at various locations, ‘traffic light’ pattern may form, ultimately familiar wing-tip (trailing) develops. In contrast, flow downstream less slender 1 0.5 large vortices, which become asymmetric with incidence. Close 0.5, small angles only, unique inner concentrations, opposite sense rotation main found part