Wake Dynamics Resulting from Trailing-Edge Spanwise Sinusoidal Perturbation

Abstract

The investigation identified and characterized the changes in the near wake of a bluff body produced by trailing-edge spanwise sinusoidal perturbation, which resulted in an overall reduction in the base drag. This study investigated a flat-plate body with an elliptic leading edge and blunt trailing edge, with and without trailing-edge spanwise sinusoidal perturbation. Base-pressure measurements were used to quantify the base-drag reduction associated with spanwise sinusoidal perturbation. In addition, particle-image-velocimetry measurements were performed in the near wake with and without spanwise sinusoidal perturbation, and a proper-orthogonal-decomposition analysis was used to analyze the velocity data. The findings suggest that the spanwise sinusoidal perturbation redistributed the relative kinetic energy, which enhanced the streamwise vortices and suppressed the von Kármán–Bénard vortices as a result.