Author(s): Donggeun Yoo; Joongcheol Paik
Linked Author(s): Joongcheol Paik
Keywords: Backword-facing step; Open channel flow; Large-eddy simulation; Coherent structures
Abstract: Turbulent open channel flow over a backward-facing step is reproduced at Reynolds number of 23,400 and Froude number of 0.22 using a large-eddy simulation with the localized dynamic subgrid kinetic energy model and a volume of fluid approach for capturing the free surface deformation induced by the Kolk-Boil-type vortices. The numerical solutions are comparable to the experimental measurements in terms of profiles of timeaveraged velocity, turbulence intensities and Reynolds shear stress. The three-dimensional dynamic behaviors of turbulent flow structures associated with flow separation, reattachment and two-kind of vortices shedding from the separation and reattachment points, respectively, are elucidated by aid of flow visualization technique and statistical analysis.