Investigation of a Dielectric Barrier Discharge Plasma Actuator to Control Turbulent Boundary Layer Separation

Abstract

A numerical investigation was carried out to explore the effects of a dielectric barrier discharge (DBD) plasma actuator on a three-dimensional incompressible, separated flow. The test article selected for the simulations was the National Aeronautical and Space Administration (NASA) wall-mounted hump model. The simulations were run at a Reynolds number of 936,000, based on hump chord length, and a freestream Mach number of 0.1. Hybrid partially averaged Navier–Stokes/large-eddy simulations (PANS/LES) were completed using CALC-LES, a well-validated computational fluid dynamics (CFD) code, developed by Chalmers University of Technology. The baseline code was modified to simulate the effects of the actuator, which were modeled as source terms in the momentum equation and were assumed to be steady and constant in the span-wise direction. The numerical simulations were carried out for a baseline (no control) case and five plasma control cases. To optimize the performance of the actuator, the variation of actuator location and voltage frequency was investigated. For the baseline case, a comparison of time-averaged skin friction, the coefficient of pressure, and velocity profiles was made of the available experimental results. The results of the baseline case showed good agreement for a hybrid turbulence model, thus strengthening the solver’s ability to predict a three-dimensional separated flow with reasonable accuracy. The results with the plasma actuator turned on showed improved flow characteristics compared to the baseline simulations by reducing the region of separated flow. The actuator placed just downstream of the separation point at an operational frequency of 5kHz completely eliminated the separated flow for our test conditions.

Numerical investigation of virtual control surfaces for lift control on NACA0015 airfoil

“…Once away from the wall or further downstream, velocity fluctuations decrease rapidly due to the viscosity effect. Therefore, many studies on macro flow control actually ignore the impact of the cyclical change [45][46][47]. In addition, it should be reasonable that consider that such a small local induced flow velocity fluctuation has limited influence on the large-scale flow control with large free-stream velocity (such as tens of meters per second), especially for flow around the non-stall airfoil that is the focus of this paper.…”

“…Many studies have confirmed that the most effective position of separation control is near the natural separation point, and the actuator in the deep separation zone will almost completely fail [37,47,56]. Moreover, the natural separation point moves upstream with the angle of attack, which means that a single actuator cannot always be in the best position.…”

Control of a Supersonic Inlet in Off-Design Conditions with Plasma Actuators and Bleed

“…Some studies were performed on the possibility of controlling the flow by an off-body energy addition [19,20]. Alternatively, several research efforts have been devoted to the development of plasma actuators in which the air close to the wall is locally ionized by an electrical discharge [21][22][23][24][25][26][27]. This technology was also investigated for controlling flow separation in rocket nozzles for space launchers [28].…”