Visualization of Multi-Scale Structures for Different Initial Conditions of Turbulent Wake Using Wavelets

Abstract

The turbulent structures of various scales behind the solid and porous wake-generating bodies with the same characteristic dimension have been studies by the wavelet vector multi-resolution technique. Making a comparison of instantaneous sectional streamlines of various scales obtained with each wake generator, it was found that the behavior of large- and intermediate-scale structures in wakes depends on the initial conditions and the small-scale structures is independent of the initial conditions. The most significant contribution to Reynolds stress and turbulent energy appears to come from the large-scale and rib-like structures in the cylinder wake. In the screen wake, however, only the large-scale structure exhibits more contribution.