Applicability of LES (Large Eddy Simulation) technique to wake flows past a bluff body should be clarified in order to improve numerical accuracy for the estimation of aerodynamic forces and pressures acting on a bluff body. Here, we carry out both of LES and PIV (Particle Image Velocimetry) for wake flows past rectangular cylinders with depth/breadth ratio ranging from D/B=2.00 to 3.00 at Re=2,000 and 20,000, which sensitively change turbulence structures due to flow separation and reattachment. In LES, we use the dynamic Smagorinsky-type SGS model. Firstly, at Re=2,000 where the pure turbulent viscosity is realized, the accuracy of the SGS modeling for prediction of not only aerodynamic characteristics but also turbulence statistics in the wake of rectangular cylinders are examined in comparison with PIV data. Furthermore, at Re=20,000 where the numerical dissipation must be incorporated, we clarify unfavorable effects of the numerical dissipation on the turbulence structures in the wake.
