Dynamic Stall Control of a Low Reynolds Number Airfoil with a Separation Bubble Control Blade

In the present paper, a two dimensional numerical analysis of the dynamic stall phenomenon associated with unsteady flow around the NACA 0012 airfoil at low Reynolds number (Re ≈ 130000) is studied. For this purpose, a thin blade with height of 0.005 chord length was placed vertically on the airfoil to control the bursting of the laminar leading edge separation bubble. The numerical simulation of flow is based on discretization of convective flaxes of the turbulent unsteady Navier-stokes equations by second-order Roe’s scheme and an explicit finite volume method in a moving coordinate system. Because of the importance of the time dependent parameters in the solution, the second-order time accurate is applied by dual time stepping approach. Three oscillating patterns with different frequencies and angular amplitudes were used to study the dynamic stall phenomenon. In order to validate the operation of computer code, some results for static and dynamic stall are compared with experimental data. The results of this study showed that the burst control blade had the acceptable effects on the dynamic stall control; so that these effects were increased while the oscillation frequency was raised. The best result occurs in 5 deg angular amplitude and reduced frequency of 0.15; so that the lift stall reduced 50% and there was not any obvious stall in drag coefficient.