Abstract
Unsteady airfoils develop a vortex flow in the vicinity of these walls and induce a delay in separation and the generation of reverse Karman-vortex streets by unsteady motions. These phenomena have attracted attention in industry due to the effect of the fluid force acting directly on objects. Moreover, elastic moving parts (wings or tail flukes) of flying and swimming animals have attracted a great deal of attention. We believe that the "elastic deformation" and "unsteady motion" strongly affect the generation and development of the fine vortex structure, which is origin of wake structure in the vicinity of a wall. However, the behaviors of vortices on the surface of unsteady airfoil have not been clarified in detail. The authors performed the PIV measurement for vortex flow in the vicinity of a wall of the elastic NACA0010. We focused on the relative angle of attack generated by heaving motion and elastic deformation and clarified the effect of relative angle of attack to the developing process of vortices generated in the vicinity of a wall.
