The Analysis of Flow Around a 2-D Airfoil at Low Reynolds Number

Using high order finite difference scheme,a direct numerical simulation (DNS) of low Reynolds number flow around a NACA0012 airfoil was carried out.The Reynolds number based on chord is 1.0×10.4,the angles of attack are 0°,4° and 10°.The computation results indicate that the statistical traits of wake region are similar at angles of attack 0° and 4°.In the wake region distancing trailing edge 0.3 chord,ordered vortex streets exist,the extremum of vorticity and minimum of pressure are located in the center of vortices.Along the streamline,the absolute value of vorticity decreases gradually,while the minimum of pressure increase step by step.The statistical traits of wake region at angle of attack 10° are different from that at other two angles.The absorption of vorticity and formation of high pressure region are two conditions of vortices shedding.