| This study considered a numerical simulation with LES modeling of combined wavy and steady flows past a vertical circular cylinder. The numerical simulation considered the time-dependent, three-dimensional, incompressible Navier-Stokes equations in polar coordinates using primitive variables with a combined spatial approximation of the central differencing scheme and the Fourier spectral method. Fourier spectral methods were used in the circumferential and axial directions. A combination of Dirichlet and spatial Convective Projection boundary conditions is implemented to assure traveling waves, from the time-dependent flow structures formed at the cylinder surface, to be convected undisturbed outside the flow field. Verification and validation of the numerical model were conducted to ensure convergence, stability, accuracy, and repeatability of the numerical model. The results obtained from our model were compared to well-recognized numerical studies of a steady approach flow, a purely wavy flow, and two-dimensional combined steady and wavy flows past a circular cylinder. These results are in good agreement with the previous work done.;This study shows the significant effects of such combined flows on forces exerted on the cylinder, the effects of combining the steady flow and the wavy flow on the drag and inertia coefficients and the changes in vortex patterns due to that combination. It also extends the present understanding of the effects of the frequency parameter, the Keulegan-Carpenter Number, and the strength of the steady flow on the mechanics and the behavior of flow around the cylinder.;It is noted that the drag and inertia coefficients of the combined flows are reduced with the increase of the strength of the steady flow.;Finally, this study has shown that the numerical simulation used in the present work gives good representations for steady flow, wavy flow and the combination of the two flows for the forces exerted on the cylinder, force coefficients and the vortex patterns in the wake. |
