Numerical simulation of active dynamic stall control on an OA212 rotor airfoil

In this paper, the active dynamic stall control using synthetic jet on an oscillating OA212 airfoil at high angle of attack is simulated and discussed. Cell-centered finite-volume scheme is used to discrete the unsteady Reynolds-Averaged Navier-Stokes equations of integral form. An AUSM⁺-up upwind scheme and a fully implicit dual-time step method are utilized for spatial discretization and time stepping, respectively. Implicit preconditioning method and geometric multigrid method are also both employed to remove the stiffness encountered in simulation of low-speed flows and accelerate the convergence of computation. The influence of synthetic jet on the main flow is modeled by a generalized unsteady blowing/suction boundary condition. Different types of jets at different locations are simulated, and the influence of frequency, phase shift, jet angle and momentum coefficient on the outcome of control are studied. It indicates that synthetic jet is well suit for reducing the hysteresis loop and improving the maximum lift, and it is found that the combination of synthetic jets located at 12%c and 62%c from the leading edge is an optimum control strategy.