Turbulent flow characteristics around a non-submerged rectangular obstacle on the side of an open channel

The three-dimensional flow structure and turbulence characteristics around a non-submerged rectangular obstacle in an open channel are explored using numerical simulation. In particular, a low length-to-depth ratio condition, shown to be associated with three-dimensional flow features in our previous study, is considered. To sufficiently resolve all the important details of the three-dimensional turbulent flow around and in the entire wake of an obstacle, high-resolution large-eddy simulation (LES) employing is carried out on a parallel supercomputer. The LES results were compared with the measurements and analyzed to examine the horseshoe vortex structure, free-surface vortex structure, recirculation zones, vortex shedding process, turbulence characteristics, and wall shear stress distribution around an obstacle. The results provide important insights into the complete three-dimensional flow structure and wall shear stress patterns around the obstacle.