Abstract
Flow separation occurring around a bluff body causes pressure drop on the rear surface and formation of vortices in the wake, which eventually cause drag increase and structural vibrations. Various types of flow controls, both passive and active controls, have been studied to remedy such problems. Recently, a plasma actuator has attracted attention as a novel device for active control. It is composed of two electrode and dielectric layer between them. High AC voltage produces plasma between these electrodes and induces body force onto the flow. In the present study, flow around a circular cylinder with plasma actuators installed on its surface is investigated by means of direct numerical simulation (DNS). The plasma actuators are placed at ア90-from the stagnation point. Four different cases are examined: no control, two-dimensional (2D) forcing, and two types of three-dimensional (3D) forcing. The simulation result suggests that the 2D forcing is the most effective in reducing the drag, but it increases the lift fluctuation. The 3D forcing is found to be effective in reduction of both drag and lift fluctuation.
