抄録
In recent years, considerable research efforts in a number of institutions have been devoted to advancing understanding of the unsteady effect, because the effect of unsteady fluid forces must be important to the flight mechanism. In the present study, the unsteady fluid forces and vortical flow field were measured during upward movement by changing the angle of attack impulsively in a wind tunnel test. In order to better understand the relationship between unsteady fluid forces and the three-dimensional vortex behavior, a PIV technique in a scanning light-sheet in the spanwise direction was also used to examine the flow field around the airfoil. The unsteady fluid forces were affected by the vortex behavior on the upper surface of the airfoil during upward movements.
