Abstract
The multi-scale structures of turbulent wakes generated by three kinds of body (circular cylinder, square cylinder and compound of cylinder and square cylinders) have been experimentally investigated in this study. Firstly, the instantaneous velocity fields and vorticity were measured by PIV technique in a circulating water channel. Then a two-dimensional wavelet multi-resolution technique was used to analyze the instantaneous vorticity measured by PIV, and turbulence structures were decomposed into a number of subsets based on their central frequencies, which are linked with the turbulence scales. Vorticity of various frequencies were examined and compared between the three generators.
