Time-averaged Image of Coherent Structures in Turbulent Open Channel Flow

Abstract

Coherent structures in turbulent open channel flow are investigated using flow visualization and their images processing techniques. In this method, tracers distribution on Z-T plane, Y-T plane are processed from the streamwise view of flow visualization using fluorescent dye illuminated by a sheet of laser light. Through taking pictures of them by CCD camera, the images are acquired. After the images get binary processing, they are analyzed statistically. As the result, instantaneous images, time-averaged images, and hierarchy of the coherent structures in turbulent open channel flow are considered.