Effect of Shear Intensity on the Wake Characteristics of a Sphere

A three-dimensional numerical study is performed on uniform shear flow past a sphere using Open Source Field Operation and Manipulation (OpenFOAM) at Re = 300. Shear intensity (K) is varied from 0 to 0.125 in such a way that the Re remains fixed equal to 300. Iso-Q surfaces have been plotted to determine the effect of shear intensity on the wake structures. It is found that the flow maintains a plane of symmetry for all values of K. Symmetric plane coincides with the X–Y plane for non-zero values of K. Strength of hairpin shape vortices increases as the value of K varies from 0 to 0.125. Qualitative analysis of the wake oscillations has been carried out with the help of the Hilbert spectrum of a transverse velocity signal in the wake. Marginal Hilbert spectrum has been plotted of a transverse velocity signal to determine the effect of K on vortex shedding frequency.