Numerical Simulation of Dynamic Stall Phenomenon of a Pitching Airfoil

In this research, fluid flow around a pitching airfoil in dynamic stall is simulated by numerical method and the most important impact of parameters on the aerodynamic forces are investigated. In this simulation, the geometry is NACA0012 airfoil. turbulent flow and dynamic grid was used. The basic equations are discretized based on the a control volume method and solved by the PIMPLE algorithm with an open source code, OpenFOAM. Reynolds number was 105 and SST K-ω model is used for modeling of turbulent flow. First, the results were compared and validated with experimental data. Then the effect of Reynolds number, reduced frequency, amplitude and airfoil thickness on the aerodynamic coefficients and dynamic stall location are investigated. The mentioned parameters on maximum lift coefficient, drag coefficient, the ratio of the aerodynamic coefficients and the dynamic stall have asignificant impact. However, these parameters dont have a significant impact on the slope of the lift coefficient curve. Among the above-mentioned parameters, the most important parameter that affects the ratio of the maximum lift to drag is the airfoil thickness and the most important parameter that plays a role in delaying the dynamic stall is reduced frequency. Also, the location of separation point and maximum aerodynamic forces depend on the flow pattern around airfoil.