Postponing transition to turbulence in the swept wing boundary layer by means of stationary disturbances control using plasma actuator

Control of a laminar-turbulent transition, driven by cross-flow instability in a swept wing boundary layer, is attempted using close-loop suppression of natural stationary disturbances. To fulfill this task, a control system based on multichannel plasma actuator, particle image velocimetry-base sensor and controller was designed and built. Control was based on the closed-loop optimization of the actuator voltages, implemented by gradient descent algorithm. Control was implemented for the stationary cross-flow vortices excited by isolated roughness on the plate surface. Reduction of the disturbances amplitude was achieved, with a significant downstream shift of the transition region.