抄録
In order to clarify the influence of an interaction between defomiable surface and its surrounding flow field, this study has been carried out using cylinder models having an elasto-flexible surface which simulates the skin of dolphins. The deformation of the surface and the flow field around the model were observed using a laser light sheet visualization method. The visualization result showed that there were three different kinds of travelling waves generated on the surface, namely, continuously-occurring wave, unstable-wave occurring at high-speed stream, periodically-occuning wave. Especially, in the third case, the traveling waves (TW) were observed to occur as every Karman vortex is shed from the cylinders. When silicon oil whose viscosity was about 20 times higher than the water's one is contained in the cylinder, the domain of the appearance of the continuously-occurring waves pattern was shifted and extended high ratio of the models sectional area. It is suggested that generation of the traveling wave is caused by flow separation on the surface of cylinder. And wavelength of TW is 20% shorter and traveling velocity of TW is slower than the case of water contained.
