Control of the secondary crossflow instability using Plasma Actuators

Abstract

Direct numerical simulations are used to investigate the fundamental applicability of plasma actuators for controlling laminar breakdown in a sweptwing- type boundary-layer flow. Localized volume forcing, modelling the actuators, is used to favourably influence the three-dimensional nonlinear disturbance statewith large-amplitude crossflow vortices (CFVs). One actuator per fundamental spanwise wavelength is positioned at a selected spanwise position to alter the CFVs and the associated flow field. It is found that both forcing against and in the direction of the crossflow can weaken the secondary instability and thus delay transition to turbulence.