Prediction of active flow control performance on airfoils and wings

A numerical investigation of active flow control, which can offer significant improvements to aircraft wing, helicopter and wind-turbine rotor performance by suppressing detrimental effects of separated flow, is presented. Numerical simulations of pulsating jet flow control applied on airfoils and wings at low speed, high Reynolds number turbulent flow and fixed angles of incidence are carried out. Pulsating jet active flow control is applied as a surface boundary condition and the flow is time-dependent. It was found that fine grid resolution is required to capture the pulsating jet and its interaction with the boundary layer. Efficient, implicit, time-accurate numerical methods for unsteady RANS of incompressible flow are used to overcome the stringent stability limitations imposed by small grid spacing. A widely tested one-equation turbulence model is used for the prediction of the complex, unsteady flowfields. It is found that active flow control can enhance aerodynamic performance by reducing the adverse effects of separated flow. The effect of pulsation frequency, and jet exit velocity on flow control is investigated.