Abstract
The main object of this study is to present an experimental investigation of the relation between the deformation of flexible surface and hydrodynamical force acting on a circular cylinder in uniform flow. Thin rubber film is folded on a circular cylinder keeping a small gap where water is filled up. The cross-sectional form of the circular cylinder is visualized by applying a laser light sheet. A strong deformation caused the sharp fluctuation of brightness in image. Then classification of image and ridge tracing technique is applied to image analysis of shape determination. It is proved that amplitude of shape deformation isclosely related to the variation of hydrodynamical force.
