Numerical Investigation of Flow in Various Types of Vertical Slot Fishways and the Function of Baffles

摘要

Hydraulic structure in vertical slot fishways with12 designs is numerically investigated and the effect of baffles of the fishways on the hydraulic structure is discussed. The numerical model employed is based on the finite volume method of the shallow water flow equation discretized on quadtree grids with a Godunov-type scheme. The vertical slot fishway models consist of 9 pools with width and length of 2.0 m and 2.2m, 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. Based on the numerical investigations, it is concluded 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. Hence, both kinds of baffles are indispensable for vertical slot fishways.