Numerical and Experimental Analysis of Plasma Flow Control Over a Hump Model

Turbulent flow separation over a wall-mounted hump model and its control using plasma actuators were studied numerically and experimentally. The hump model chosen in this study was that used in a 2004 NASA Langley CFD validation workshop for turbulent separation control using synthetic jets. The numerical simulations solved the Reynoldsaveraged Navier-Stokes equations using Fluent. Different turbulence models based on k-ε, k-ω and SA were investigated. All turbulence models did a reasonable good job predicting the overall features of the flow fields, but only the k-ε model agreed well with the experimental data in terms of the skin friction coefficient. A body force model was used to simulate the effect of the plasma actuator. These results showed that the plasma actuator could be effective in controlling the turbulent flow separation over the hump. Both spanwise and streamwise plasma actuator configurations were investigated experimentally at a Rec = 288K. A smoke wire was used to visualize counter-rotating vortices generated by the streamwise plasma actuators. An optimum spacing between the exposed electrodes of the streamwise plasma actuator was found. Surface pressure coefficients demonstrate both streamwise and spanwise configurations work well for turbulent separation control.