Plasma-Based Flow Control for Delay of Excrescence Generated Transition

Abstract

Numerical simulations are carried out to explore flow control that delays transition generated by excrescence on a platelike geometry in subsonic flow. Both forward-facing and rearward-facing steps of small roughness heights are considered in the simulations. These are representative of joints and other surface imperfections on wing sections that disrupt laminar flow, thereby increasing skin friction and drag. Dielectric barrier discharge plasma-based flow control is employed to delay transition and increase the extent of the laminar flow region. Solutions are obtained to the Navier–Stokes equations, which were augmented by source terms used to characterize the body force imparted by a plasma actuator on the fluid. A simple phenomenological model provided these forces resulting from the electric field generated by the plasma. The numerical method is based upon a high-order numerical scheme and an implicit time-marching approach on overset mesh systems used to describe the steps. Very small-amplitude numer...