The Application Of Numerical Simulation On Shape Optimization Test Of Spillway Tunnel Facilities For Cavitations’ Mitigation

Artificial aeration facilities can effectively reduce the cavitations inspillway cave, But the Shape design of aeration facility lack of reliable designtheory. In the design process, Hydraulic model test is commonly used to verifythe design scheme, and proposed an optimization scheme. Make the shapeoptimization by model test has more limitations; use numerical simulation toauxiliary the model test can effectively solve this problem.This article systematic exposition the generation mechanism of thehigh-speed flow cavitations in spillway tunnel, summarizes the principle andResearch ideas of artificial Aeration, proposed the specific ways of shapeoptimization by summary of the various theories. After determine the optimalway, develop a reasonable testing program by in-depth study of the numericalmethods and test standards, Euler model is selected as the numerical modelaccording to the actual situation, and then dish the corresponding numericalcalculation process.This study example is a typical high head spillway tunnel, and selects theaerator1as the research object, where the cross-sectional flow rate betweenthe high-speed flow and low-speed flow. In this case, the facility of aeratoralways difficult to design, and need to optimize many times in order to get areasonable body design. In this study example, firstly, made model tests andnumerical calculations for original program in succession, Verify the accuracyof numerical calculation by Comparison of various important parameters.Secondly, using numerical simulation to make shape optimization, thishydraulic condition for simulation based on the original program, and finallyproposed an optimization scheme. Finally, in the same hydraulic condition,make model test and numerical simulation for recommended program; verifythe accuracy of the numerical calculation again. In the process of verify theaccuracy of the numerical calculation, selected the normal water level and thecheck flood level as the calculation condition, analysis the error betweencalculated and experimental results by Comparison of the water line, the roofspace, along pressure, cavitations number and gas-doped, And to analyze the possibility of errors generated; In the process of shape optimization, selectedthe normal water level as the calculation condition, determine thereasonableness of the Body design by analyzing the form of the cavity andmixed gas-doped, if the previous scenario is unreasonable, according to theprinciple and research ideas of artificial aeration, adjust the structural designuntil find a reasonable solution. This study example shows that: therecommended solution of numerical verified by model test, and the numericalresults were close to the experimental results.