Abstract
We have carried out experiments to measure velocities of turbulent water flow over two wavy plates on the bottom of a shallow open channel at a high Reynolds number. These plates mimic the folded skin of fast-swimming dolphin. The hydrophilicity of these plates are different. Also, we have measured total drag acting on the test plates by the flow. Wall-shear stress is evaluated from the gradient of mean velocity on the plate surface. The pressure drag is calculated from the difference between the total drag and the friction drag. The friction drag of the wavy plate made of the hydrophilized polycarbonate sheet is 12.1% lower than that of silicone rubber sheet.
