Vortical Flow Effects on Flow Separation Control

Abstract

The effect of Reynolds number, oscillation frequency, amplitude, and the incident angle on flow separation control is studied numerically in this thesis. Two configurations are investigated, cylinders in tandem and the cylinder-airfoil arrangement. The upstream cylinder changes locations, size, and oscillating frequencies and amplitudes, which necessitates investigating its effect on separation control of the downstream cylinder or airfoil. A validation simulation based on an airfoil in the wake of a stationary cylinder is carried out to verify the numerical method that will be used in this study. The results show that high-Reynolds-number, high-frequency low-amplitude oscillation motion of the upstream cylinder reduces the flow separation on the downstream airfoil. By placing an oscillating cylinder in the upstream, the flow separation point moves slightly further downstream even at zero angles of attack.