Numerical investigation on the effect of baffles on flow in vertical slot fishways.

Hydraulic structure in vertical slot fishways with 13 designs is numerically investigated and the effect of each baffle on flow in the fishways is discussed. The numerical model employed is based on the finite volume method of the shallow water flow equation discretized on quadtree grids with the Roe’s scheme for discretizing inviscid terms. The vertical slot fishway models consist of 9 pools with width and length of 2.0 m and 2.2 m, respectively. The width of the slot at each pool is 0.25 m and the bottom gradient of the fishway is 1/20. Each pool is framed by at most three types of baffles: main, short and guide baffles. The conducted numerical investigations demonstrated that the short baffles decrease the main stream velocity by enhancing meandering of main stream and the guide baffles suppress excessive meandering to create calm recirculation areas in the pools.