3D computations of Large Eddy Simulation (LES) are conducted for turbulent vortex-shedding flow past a two-dimensional (2D) square cylinder at Re = 2.2×10^4 for which detailed experimental data are available. At high Reynolds numbers, stochastic three-dimensional turbulent fluctuations, which exist even in the flow past 2D cylinder, are superimposed on the 2D periodic vortex-shedding motion. Here, the characteristics of periodic and stochastic fluctuations of turbulent vortex-shedding flow given from the 3D LES are compared precisely with the results of the water channel experiments by Lyn. Furthermore, results of the 3D LES are also compared with results of k-ε model and Differential Second-moment Closure Model (DSM), which were given from the computations by Franke and Rodi. In many respects, LES shows better agreement with experiments than does DSM, even though this is not perfect. It seems clear that the 3D LES method is best suited to cope with the very complex vortex-shedding flows.
