Experiment Study About Attractive Effects For Fish In Different Flow Velocity At Ship Lock Model

The main principle of fish passage facilities is that lurethe fish into the fish passageuse of fish’s rheotaxis,and make fish free back to a dam upstream.The main problemisthat ensuring imports have suitable velocity, flow pattern and suitable for fish survivalenvironment factors (including water temperature, DO, pH, etc.), to lure fish and facilitatethe fish into the fish passage facilities.Therefore, to validationfeasibility of fishthroughthe Lock, you first need to explore the lock for close brake operation mode andlock water filling process of regional water environmental impact and close brakeregional response of fish in the aquatic environment change and the most suitable for fishlure flow condition, etc.Gezhouba lock acts as the research object in this paper, the activity patterns of fishnear the gate area and the major factors that affect fish distribution has been provedduring the lock gates open and close, charge and turn on the water, and fish areemphatically analyzed the response of the velocity change near the gate by on-sitemonitoring. The flow parameters, such as optimal flow rate, flow pattern, turbulent energy,turbulent energy dissipation rate, has been explored, which are fit for inducing the fish toget into the lock, and the measures that the current induces the fish to get into the lock areput forward, and the feasibility of making use of the current induces the fish to get intothe lock is analyzed, By means of test that the current induces the fish to get into the lockon lock model and numerical simulation of flow field. In this paper.The specific resultsare as follows:1) Shiplock running state for effect on trap fishLock different operating conditions for downstream river water temperature, DO, pHhad no significant effect, impact on downstream water flow rate is bigger.During the run offish density and lock status correlated significantly, lock gates open drain, fish density wassignificantly increased.At this point, in the upper lock downstream flow rate is between0.2m/s to0.5m/s, the flow rate is induced velocityof fish or just like the flow rate range,the fish will show a trend along with the flow goes back.So the flow rate has some inducedto the fish near the gate area in this time period.2)Experimental study on the flow of induced fishThe study found that, the same water level and flow velocity, the gate opening is75°(i.e. the gate width is49cm), the best effect of luring fish. At the same level and the degree of opening, the flow rate was0.45m/s, the best effect of luring fish. When the otherconditions are the same, the change of water level is not the effect of luring fish effect.Conditions of2-2-4(i.e. water level is0.24cm, gate opening75°and flow velocity of thewater is0.45m/s) was the best condition. Velocity range of0.4~0.6m/s fish lure effect ofexperimental group is superior to the velocity range of0~0.4m/s and of more than0.6m/s, along with the speed rise, fish lure effect is normally distributed. And the gate openingis75°above categories of fish lure effect is better than the group under the gate opening is75°,with the gate opening is reduced, the fish lure effect showed a trend of decline.(3) Numerical simulation analysisThe mumerical simulation for the flow in ship locks in different workingconditions,which results show that the flow in the gate of ship locks express “bottleneck”shape, the maximum flow velocity in the water near the lock gate narrow area. Surfaceflow velocity is larger than the bottom velocity and flow disturbance area is near the lockgate shaft.Additional,the The flow regime in working condition2-2-4(the water level is0.24m,lock gate opening is75°, velocity is0.45m/s)is similar to the counterpater2-3-4(the water level is0.24m,lock gate opening is60°, velocity is0.45m/s),howeverthere is something differences for them,for example, The reflux area in the workingcondition2-2-4is larger than that in the2-3-4,and the maximum flow velocity far lessthan that in the condition2-3-4which up to1.1m/s.Meanwhile, the The flow regime,turbulence kinetic energy, Turbulent kinetic energy dissipation rate in working condition2-2-4is all smaller than that in condition2-3-4. In conclusion,we think the flow in wokingcondition is more suitable for inducing fish to through ship locks gate and finally into thelock chamber,also the reflux area with the relative slow velocity provides a good restcondition for the upstream fish.The flow in the end of approach channel is smoother than that in lock gate,on theother hand, the maximum flow area located in the upper level of middle section,there isnothing difference for flow situation in the distinguish working condition.But the mumberof maximum flow velocity have a divergence, maximum flow velocity in workingcondition2-3-4is two times greater than that in2-2-4,while under the working condition2-2-4,it is more conducive to guide fish to enter lock chamber from downstream whenhaving the large district with0~0.40m/s velocity scope.(4) Fish lure measures and feasibility analysisFish measures should flow as the main lure fish lure medium, choose appropriate sound, light, electric current as auxiliary induction medium, each factor consideringsetting, to lure the fish displacement effect maximization as the goal as a whole.Throughthe design, construction, maintenance and management theory into consideration, such aslock water fish lure have the feasibility.This study is based on fish behavior and hydraulics experiments.The process andconclusion of the study can provide reference for fish hydraulics experiments.At the sametime, this research will be guided and improved the research and construction of fishpassage facilities, and has important theory value and practical significance forhydropower engineering enterprise’s long-term development.