Abstract
In the present paper, we examine organized motions along a turbulent mixing layer in an open-channel flow analyzed by using wavelet transforms. Experimental data of velocity vectors are collected from a particle image velocimetry (PIV). At first, a multiresolutional analysis (MRA) is employed for extracting a velocity component of organized turbulence from the PIV data. Then, distributions of an instantaneous Reynolds stress in the organized turbulence are analyzed using a two-dimensional continuous wavelet transform (2D-CWT) in order to detect the spatial scales and their locations of the coherent structures. From the results of the wavelet analyses, characteristics of the organized motions along the mixing layer, such as an evolution of spatial scale, advection velocity and intensity of the instantaneous Reynolds stress, are discussed in different Froude number.
