Font Size: 

In the present work, the hydrodynamics in a straight open channel constructing a multiple-embayment groyne field on one of its sides is investigated by numerical simulations. The open channel is composed of a flat bottom in the main channel and a gradual slope toward one of the sides with a ratio 1:3. A series of five embayment are constructed on the slope, and the ratio of the embayment's length to width is specified as 3. A thorough analysis of the three-dimensional flow characteristics was carried out by Zonal detached-eddy simulation (ZDES) model. The numerical simulation highlights the turbulent coherent structures induced by groynes, including local horseshoe vortex (HV) around the groyne tip, shedding vortex (SV) from the groyne and the mixing layer flow at the channel-embayment interface. Both the instantaneous and the mean flows show a spatial evolution of turbulence in the main channel and embayment, which reveals different coherent structures from the upstream embayment to the downstream embayment. The analysis of the large-scale eddies, which populates the mixing between the channel and embayment, are contributed to investigate the mechanisms of fluid mixing, mass transportation and exchange, and some issues about hydraulic engineering.