Abstract
The transient aerodynamic characteristics of the unsteady force are investigated by varying impulsively the incidence of the airfoil beyond the stall angle. In this study, we measured unsteady fluid force acting on the airfoil simulating a human hand in swimming using load cells and visualized vortices in the wake in a wind tunnel. We also examined the relation among fluid force, angle of attack, and rise time. As a result, impulsively varied incidence makes an angle of the static stall larger and also the lift coefficient larger. We investigated the dynamic flow vector and vorticity fields at Reynolds number 1.O×10^5.The vortex shedding from the airfoil cause s the changes in the transient characteristics.
