Abstract
We have carried out experiments to measure velocities of turbulent water flow over a wavy plate with symmetrical ridgelines on the bottom of a shallow open channel at a high Reynolds number.This plate mimics the folded skin of fast-swimmmg dolphins.Also,we have measured total drag acting on the test plate 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 friction drag.The results show that a certain reduction of the wall-shear stress occurs particularly near the side of the plate.Our results indicate that an increase in the pressure drag is reduced.
