Large Eddy Simulation of Turbulent Flow Past a Circular Cylinder

초록

Large Eddy Simulation (LES) of turbulent flow past a circular cylinder for the specified Reynolds numbers (Re = 63100, 126000, 252000) were conducted to capture the drag crisis phenomenon. The 3D LES code to be used in the present study has been developed in-house by the authors in a finite-volume framework. An immersed boundary method was employed to facilitate implementation of a circular cylinder in a Cartesian grid system. A Lagrangian Dynamic Subgrid-scale Model, in which the model coefficient is dynamically determined by the current resolved flow field rather than assigned a prefixed constant, was implemented for accurate turbulence modeling. For better resolution near the cylinder surface and in the separated free-shear layers, a composite grid will be used. All the requested flow data including but not limited to time series of CD, CL, and their mean/RMS values, Strouhal numbers of vortex shedding, flow visualization using streamlines and vorticity contours will be presented.