Extraction of a multiscale structure of a turbulent lobed jet from PIV results using a vector wavelet multiresolution technique

Abstract

The wavelet-based vector multiresolution technique was applied to the postprocessing of PIV results for identifying the multiscale turbulent structures of a lobed jet. By analyzing the instantaneous streamlines and vorticity fields of various scales, we obtained important information on the multiscale flow structures. The large-scale vortices or coherent structures with a central scale of a = 15.36 mm were easily extracted from PIV measurement results. The intermediate- and small-scale vortices embedded within the large-scale vortices were separated and visualized.