Investigation of characteristics of fluid field over wavy beds under oscillatory flow
振荡流作用下波状底床上流场特性的实验研究

Particle Image Velocimetry(PIV) has been used to measure the oscillatory flow above three fixed wavy beds in the U-type tank.And the instantaneous velocities and vortices at several amplitudes have been acquired.By analyzing the circulation and trajectory of vortices with varied phases,the influences of beds geometric characteristic on the flow closed to the beds have been carried out.All of these indicate that the wavy beds geometric profiles determine the characteristic of vortex field and the vortex trajectory and the net sediment transport.The conclusions are significant to study the mechanism of sediment transport over wavy beds such as sand waves,ripples and dune for the coastal environment.