Modeling of Turbulent Flow Past a Circular Cylinder Using Large Eddy Simulation on Unstructured Grids

ABSTRACT: In this work, a computer program is written for solving the turbulent flow equations on unstructured grids using a Large Eddy Simulation (LES) model in C++ language. To test the code, two cases are considered: laminar, periodic flow past a circular cylinder at Reynolds number, ReD = 100 which is based on the diameter of the cylinder and turbulent flow at ReD = 3900. The turbulence or sub-grid scale (SGS) model is chosen as Smagorinsky model due to its simplicity compared with dynamic models. It was found that, for the laminar case, drag, lift, and back-pressure coefficients, pressure and velocities matched quite well with the reference values obtained from literature. For the turbulent case of ReD = 3900, there is some discrepancy between the results of the present investigation and the results obtained from other resources which is due to rather coarse grid distribution dictated by the insufficient computing resources. Keywords: Computational fluid dynamics, circular cylinder, large eddy simulation, unstructured mesh, turbulence. ……………………………………………………………………………………………………………………………………………………………………………………………………………………