Study On The Hydraulic Characteristics Of The Side Floodgate Spillway And The Shape Of Nose Scourer

Discharge structure bear more important flood discharge functions and play an important role in the hydro-junction project.The normal operation of discharge structures relates to the safety of the hydro-junction project.The side weir of spillway has been used in many miniature and medium hydro-junction projects in recent years.At present,the research on the side weir of spillway focuses on the overflow capacity and energy dissipation form of the overflow weir.Due to the limitations of high water heads and topographic conditions,the issue of flood discharge and energy dissipation of dams has attracted attention from scholars.In the case of the side weir of spillway,the energy dissipation of the deflecting flow is often used due to the advantages of good energy dissipation,convenient construction,and low investment.The paper takes the side weir of spillway of a reservoir as the research object,the water inventory is narrow in the downstream valley,and the structure of some bank slopes is not stable.Model tests were performed to study the hydraulic characteristics of flow field on spillway under different conditions.The FLUENT software was used to simulate the spillway and the characteristics of the flow field under the flood level were analyzed.The correctness of the numerical simulation results was verified by comparing the physical model test data.The optimization of the contraction ratio(the ratio of the exit width b to the inlet width B)is optimized for three aspects,namely the optimization of the flip bucket of the side weir of spillway for problems such as the horizontal length of jet flow is less.And through the numerical simulation to draw a better form of the flip bucket.The conclusions are as follows:(1)Scheme I(contraction ratio is 0.6).the peripheral wall height of narrow-gap energy dissipater meet the design requirements.the water depth in region of contraction on flip bucket is less,but increase of the horizontal length of jet flow is not obvious.(2)Scheme 3(contraction ratio is 0.3).the horizontal length of jet flow is significantly increased.the water depth has increased rapidly in region of contraction on flip bucket,so the former design of peripheral wall height needs increase.(3)Scheme 2(contraction ratio is 0.4).the water depth in region of flip bucket is increased,appropriate increase of height of spilway peripheral wall,and will strengthen increase the horizontal length of jet flow.By considering factors such as throw distance and construction quantity,optimization model 2(contraction ratio of 0.4)was superior plan.The results of simulation and analysis are verified by model tests.The research results can provide reference for similar practical projects.