Numerical study of vortex shedding from a circular cylinder in linear shear flow

A three-dimensional numerical simulation of linearly sheared flow past a ci rcular cylinder has been performed for a shear parameter beta of 0.02 and a mean Reynolds number of 131.5. A cylinder of 24 diameters span is consider ed. A second-order accurate finite volume scheme is used to integrate the u nsteady Navier-Stokes Equations. Present computations confirm both qualitat ively and quantitatively, the aspects of cellular shedding as reported by s everal investigators through experimental studies. Up to five constant freq uency cells of obliquely shedding vortices are observed. The nondimensional frequencies of these cells are observed to be lower than those given by pa rallel shedding correlations at the equivalent Reynolds numbers. It is also observed that the cell boundaries continuously move in time. Detailed dist ributions of vorticity and velocity components are presented to describe th e flow. The influence of end-wall boundary conditions is studied by computi ng two cases, one with free-slip condition, and the other with no-slip cond ition on disks of radius of five cylinder diameters.