Abstract
In this study, unsteady aerodynamical effects of 2-D airfoil (NACA0012) at the attack of angle 7deg under acceleration or deceleration condition was numerically investigated using a grid-free vortex method. The aerodynamical forces and vortical flow field were compared with each accelerated or decelerated condition at Re=4.0×10^5. In this analysis, firstly, airfoil was moved at a constant speed, and then, each acceleration or deceleration condition was given to the airfoil from the non-dimensionless time T* = 7.5 at which the fluctuation of fluid forces became stable. The result showed that the aerodynamical forces changed compared with the steady condition. In addition, pressure distribution affected by the change of the vortex structure on the airfoil appeared.
