Experimental And Numerical Simulation Study On Hydraulic Characteristics Of A New Fishway

Aiming at the problems of the traditional fish-way once completed,the flow condition is basically fixed,and difficult to adapt to a variety of fishes through,this paper presents a new type of fishway Tai Chi which can form a rich flow regime and adapt to the migration of many fishes.The main research contents are as follows:The experiment device was made for the simple Tai Chi fishway,and the indoor test of the physical model was carried out.The water level of each key section of the fishway was measured under different working conditions,and the comparison test of the fish was carried out;The computational fluid dynamics(CFD)model of the simple Tai Chi fishway was established and the three dimensional numerical simulation of the hydraulic characteristics of the fishway was carried out.The comparison of the results of physical test and model test showed that they are basically the same trend.The velocity field of fishway under different conditions with the rotation of Tai Chi disk was analyzed;Based on the CFD numerical model,the hydraulic characteristics of the refined Tai Chi-Eight Diagrams fishway were simulated and analyzed.The results showed that the new type of fishway has a good reduction effect.The shallowest water depth of the simple Tai Chi fishway is twice that of the corresponding shallowest water depth without the Tai Chi disk,the average maximum velocity of the section is 0.95m/s.Average maximum velocity of cross section decreased by more than50%,the flow presents polymorphism,Tai Chi disk's different positions also make flow change,which can provide more suitable conditions for migratory fish.The refined Tai Chi— Eight diagrams fishway has better performance in reducing energy dissipation and creating polymorphic water flow.