Numerical investigation of high Reynolds number flows over square and circular cylinders

Numerical solutions of flows at high Reynolds numbers are investigated by detached-eddy simulation (DES). Two cylinders in crossflow are selected as the test cases; flow around a circular cylinder is simulated at Reynolds numbers of 1.4 x 10(5) and 3.6 x 10(6) and simulation for a square cylinder is performed at a Reynolds number of 2.2 x 10(4). These simple geometries produce complex flow phenomena such as recirculation, vortex shedding, and unsteady turbulent separation, which are very common flows associated with complex geometries. However, most numerical simulations have been performed at low Reynolds numbers, and only a few are reported at high Reynolds numbers ranges. DES with the Spalart-Allmaras turbulence model is used for turbulent treatment. It functions as a Reynolds averaged approach in the near-wall region and transfers to large eddy simulation (LES) far from the wall. This procedure requires fewer grid points compared to LES. To assess the quality of solutions, the results are evaluated by comparison with experimental data and other numerical results. In addition, laminar solutions and trip functions are also investigated in the circular cylinder cases. Even though fewer grid points are used, most of the results compare well with experimental data and other numerical solutions.