Experimental And Numerical Simulation Study On Eddy-elimination In Front Of Sluice

When a vortex is produced before the entrance of a hydraulic structure,it will cause the deterioration of flow pattern,reduce the discharge capacity,induce the vibration of the gate and cavitation erosion,so the eddy-eliminating measures should be taken.At present,the research on the eddy current elimination is mostly concentrated in the water intake of the power station,the flood discharge tunnel,and so on.The research on the vortex in front of the sluice gate is less;the research mainly focuses on the concrete measures of the vortex elimination,and the theoretical analysis of the vortex principle is less.In this paper,through the method of model test,theoretical analysis and numerical simulation,vortex elimination in the front of the plate gate and the radial gate is studied by vertical vortex elimination barrier.The best layout scheme and the vortex elimination principle of eddy-eliminating barrier are put forward.The main work is as follows:(1)Through the experimental eddy-eliminating model test,the effects of the location and the width of eddy-eliminating barriers are studied under different degrees of opening.The study shows that two pairs of eddy-eliminating barriers' elimination effect is best in the three kinds of arrangement and no new vortex appears.(2)A specific method for measuring the height of the stagnant area is put forward,which makes the effect of water on vortex in stagnant area promoted from qualitative analysis to quantitative analysis.Taking into account the influence of inlet flow velocity and inlet shape,a quantitative formula for calculating drag force at intake is presented,which push the influence of drag from the intake port on the vortex,from qualitative analysis to quantitative calculation.(3)Comparing and analyzing the changes of the height of the stagnation area,surface circulation and the drag force of the inlet,the specific principle of the eddy current dissipation is summarized.By reducing the height of the stagnant zone,the surface circulation,and the drag force of the intake which is reduced by changing the flow velocity distribution in the inlet,the frequency of the vortex is less and the vortex area decreases.And the purpose of eddy-elimination is achieved.(4)The vortex flow field before and after the vortex gate is simulated.The numerical simulation results shows that the simulated flow pattern,surface line and streamline are consistent with the experimental results.After the layout of the eddy-eliminating barrier,the height of the stagnation zone,the surface circulation and the drag force of the intake port are all reduced in the same working condition,and the test results and theoretical analysis are verified.The research results of this paper can provide a reference for the study of vortex characteristics and vortex theory,and also provide a theoretical basis for the study of vortex measures before the gate in the actual project.