Large eddy simulation of turbulent flows in periodically grooved channel

In this study, turbulent flows in periodically grooved channel are investigated by large eddy simulation (LES). Especially, a parametric study is carried out to investigate effects of length and depth of a groove on large-scale flow structures. Comparison of LES results with those of DNS for one test case reveals a good agreement even though the number of grid points of the LES is only 6.5% of that of DNS. This confirms that LES is a suitable tool for a parametric study of turbulent flows. The subsequent parametric study using LES shows that the large-scale turbulent structures are significantly affected by the geometry of the groove. Especially, when the length of the groove is short such that the recirculation region occupies the entire groove, the turbulent flow in the groove becomes very weak in both mean and fluctuation quantities.