突扩式跌坎消力池掺气脉动特性研究  

Research on the Aeration Pulsation Characteristics of a Stilling Pool with Drop Sill and Sudden Expansion

作　　者：张红梅 假冬冬[1] 张幸农[1] 李树宁[2] ZHANG Hong-mei;JIA Dong-dong;ZHANG Xing-nong;LI Shu-ning(Key Laboratory of Port,Waterway and Sedimentation Engineering of Ministry of Transportation,Nanjing Hydraulic Research Institute,Nanjing 210029,Jiangsu Province,China;College of Water Conservancy and Civil Engineering,Shandong Agricultural University,Taian 271018,Shandong Province,China)

机构地区：[1]南京水利科学研究院港口航道泥沙工程交通行业重点实验室,江苏南京210029 [2]山东农业大学水利土木工程学院,山东泰安271018

出　　处：《中国农村水利水电》2023年第3期223-228,共6页China Rural Water and Hydropower

基　　金：国家自然科学基金资助项目(U2040215,52079080)。

摘　　要：高速入射水流进入突扩式跌坎消力池后卷入大量空气,形成掺气水流,气体的存在影响各项水力学指标,对工程安全造成影响。基于物理模型试验,对突扩式跌坎消力池的掺气脉动特性进行探究,分析其掺气脉动幅值特性、概率密度分布特性以及频谱特性。结果表明:无突扩跌坎消力池底板中线的掺气脉动幅值呈沿程衰减趋势,最大值出现在消力池首;突扩式跌坎消力池底板中线的掺气脉动幅值呈先增大后减小的趋势,最大值出现在冲击区;与无突扩跌坎消力池相比,突扩式跌坎消力池可以有效降低底板的掺气脉动强度;消力池底板掺气脉动概率密度曲线不服从正态分布;掺气脉动能量属于低频脉动,随流能比的增大而增大;突扩式跌坎消力池底板在冲击区的掺气脉动能量最大,突扩的存在可有效降低掺气脉动作用在底板上的能量。The stilling pool with drop sill and sudden expansion is an environment-friendly energy dissipater,which can adapt to high water head and large unit width discharge,has a good application prospect.After the high-speed incident water flows into the stilling pool with drop sill and sudden expansion,it is involved in a large amount of air,forming the aerated water flow.The aerated characteristics are closely related to the turbulent structure.The existence of bubbles changes the hydraulic factors such as velocity,pressure and energy dissipation efficiency,and then affects engineering safety:the aerated pulsation affects the velocity pulsation and pressure pulsation,which may lead to the resonance damage of the building.In the process of the aerated jet impacting the bottom plate of the stilling pool,in severe cases,the collapse of bubbles will peel off the concrete floor and adversely affect the stability of buildings.At the same time,relevant studies show that aerated water flow will also reduce the cavitation damage of buildings effectively and enhance the energy dissipation effect of energy dissipaters.Therefore,we should fully understand the role and impact of aerated water flow on energy dissipaters,pursue advantages and avoid disadvantages,and ensure their safe operation.At present,there are many research results on the distribution characteristics and influencing factors of aerated concentration in water cushion energy dissipation,but there is little research on the characteristics of aerated concentration fluctuation.The characteristics of aerated fluctuation of three-dimensional mixed flow in the stilling pool with drop sill and sudden expansion are still unclear,and need to be further studied.Based on the physical model test,the aeration pulsation characteristics of a stilling pool with drop sill and sudden expansion are studied,the aeration pulsation amplitude characteristics,probability density distribution characteristics and frequency spectrum characteristics are analyzed.The results show that the aera

关 键 词：突扩式跌坎 消力池 掺气脉动 概率密度 频谱特性 

分 类 号：TV131.61[水利工程—水力学及河流动力学] TV653.1