Study On Flows And Desion Optimization Of Aeration For Flood Discharging Tunnel

High-head and long straight discharge tunnel often set one or multi-stage aeratorto avoid the cavitation damage on the bottom and the side wall. The Fr of previousaerators is low. According to some correlative research, the backwater often happensin the aeration cavity when poorly designed aerator. The backwater makes the aerationcavity long or short existing or disappearing and unstable at times. Study on thespillway aerator on the characteristics and its shape optimization can solve theproblem of cavity backwater. Therefore, it is very significant to study and discuss thecharacteristics and its shape optimization of the aerator.In this paper, through the analysis of test and numerical simulation aeration,based on the previous research results, it carried out some researches and discussionsto solve the problem of the backwater of aeration cavity.First of all, it gives a brief introduction of aerator flow and its general rules.Analyze the research status and problems of spillway aeration under the low Fr. Andthe CFD numerical simulation in hydraulic engineering and research progress. Inorder to explore ways to solve the problem of cavity backwater.Then, based on the study of one high head long spillway aerator’s characteristics,it analyzed the problem of cavity backwater about the original design. And it foundthat the Froude Number is related to the depth of cavity backwater. When the Froudenumber is grater than3.5, it can form a complete and stable aeration to preventcavitation. Also, when the Froude number is less than3.5, it may optimize the aeratedcavity through change the bucket and the bucket size. Through multi-programcomparison studies, focused on the form of aerator followed by an arc-shaped floor.And it tested and analyzed its characteristics and compared with previous studies. Then it expanded the aerator research under the low Froude Number condition.At the end, it simulates the arc Cohesion of the aerator at the downstreamthrough fluent numerical simulation method. Further validate the feasibility of VOFmodel to simulate the aerator cavity shape.