抄録
It is known that flying fish perform long-range flight in the air in order to escape from predators such as tuna and swordfish. During the unsteady flight, ground effect enables the flying fish execute to flight for the maximum range and longest time. In this study, it was investigated a basic characteristic of the flow around the flying fish fin in ground effect, in order to understand the flying fish gliding performance quantitatively. The streamwise velocity profiles around the airfoil model were measured by a high time-resolved PIV (particle image velocimetry) in an open loop wind tunnel. A moving ground essential to generate the ground effect was supplied using a rotating disk. Two plates were put in tandem as the test wing model of a pectoral fin and a ventral fin of the flying fish. It was found that decreasing the height of the airfoil model caused a larger difference between the velocity in the suction surface side and that in the pressure surface side of the pectoral fin model.
