异形消力池消能机理与脉动压强特性研究

发布时间：2018-03-21 19:20

本文选题：异形消力池　切入点：跌坎底流消能　出处：《天津大学》2015年博士论文　论文类型：学位论文

【摘要】：对于高水头、大流量的泄洪工程,若应用传统底流消能形式则会由于其消力池流速高、脉动压强大,对底板的抗冲能力提出较高要求,跌坎底流消力池是近几年才出现,通过改变消力池体形来降低相关的水力学指标而达到泄洪消能目的的新型消能工,我们也称之为异形消力池。这种消能工兼有挑跌流和底流双重特点,有着良好的发展前景,对其进行研究将具有重要的工程应用价值。但从目前来看水利工作者对该消能工的相关研究还很少。因此,本文依托某两个具有跌坎底流消能泄水结构工程,通过模型试验和数值模拟相结合的方法,对消力池防护结构的水力特性进行了系统的研究。主要研究成果如下:(1)消力池底板脉动压强特性通过试验对比给出突扩式跌坎消力池相比传统消力池对底板脉动压强的降低率。找出降低底板脉动压强值的跌坎高度和突扩比,对底板体型进行优化;对于高低跌坎底流消力池,通过水力学模型试验和数值分析揭示其消能机理,总结出底板脉动压强特性及分布规律,提出使底板脉动压强最小的优化运行方案。(2)坝面隔墙脉动压强特性基于模型试验和数值模拟对隔墙下泄水流脉动压强所受各项水力学指标进行分析,探明下游水位及孔口开度对隔墙最大脉动压强影响机理,估算出隔墙最大脉动压强位置变化的经验公式。(3)导墙脉动压强特性采用水力学模型试验对作用在导墙上的脉动荷载特性进行研究,分析跌坎消力池导墙与传统消力池导墙脉动压强分布不同原因,总结出跌坎消力池导墙脉动压强变化规律。通过水弹性模型试验实测和数值计算导墙动力响应,并将试验数据与计算数据做相互对比验证。(4)脉动压强与场地振动的关系基于向家坝脉动压强试验结果结合数值分析对向家坝场地振动进行初步研究。计算出不同运行工况下各脉动荷载对场地振动的贡献率,结合前述章节各防护结构脉动压强分布规律,初步提出减振抑振工程措施,为相关工程提供借鉴经验。
[Abstract]:For the flood discharge project with high water head and large discharge, if the traditional energy dissipation form of bottom flow is applied, because of its high flow velocity and strong pulsating pressure, it will put forward higher requirements for the anti-scouring ability of the bottom plate, and it will only appear in recent years. A new type of energy dissipator, which is also called special-shaped stilling pool by changing the body shape of the stilling pool to reduce the related hydraulics index, has a good prospect for development. The research on it will have important engineering application value. But at present, there are few researches on the energy dissipator by water conservancy workers. Through the combination of model test and numerical simulation, The hydraulic characteristics of the protective structure of the stilling pool are systematically studied. The main research results are as follows: 1) the pulsating pressure characteristics of the bottom plate of the stilling pool are compared with those of the traditional stilling pool. The reduction rate of pressure. Find out the height of the drop ridge and the ratio of sudden expansion to reduce the pulsating pressure value of the bottom plate. The shape of bottom plate is optimized, and the mechanism of energy dissipation is revealed by hydraulic model test and numerical analysis, and the characteristics and distribution of pulsating pressure of bottom plate are summarized. In this paper, the optimal operation scheme of minimizing the pulsating pressure of the bottom plate is put forward. The characteristics of the pulsating pressure of the partition wall on the dam surface are analyzed based on the model test and numerical simulation, and the hydraulic indexes of the fluctuating pressure of the discharge flow under the partition wall are analyzed. The influence mechanism of downstream water level and hole opening on the maximum pulsating pressure of partition wall is investigated. The empirical formula for the location change of maximum pulsating pressure of the partition wall is estimated. The characteristics of the pulsating pressure of the guide wall are studied by hydraulic model test, and the characteristics of the fluctuating load acting on the guide wall are studied by the hydraulic model test. This paper analyzes the different reasons for the pulsation pressure distribution of the guide wall of the depression stilling pool and the traditional one, and sums up the variation law of the pulsating pressure of the guide wall of the stilling pool. The dynamic response of the guide wall is calculated through the hydroelastic model test and numerical calculation. The relationship between the pulsating pressure and the site vibration is verified by comparing the test data with the calculated data. Based on the experimental results of Xiangjia dam pulsating pressure and numerical analysis, the vibration of Xiangjia dam site is studied. The contribution rate of pulsating load to site vibration under operating condition, Combined with the distribution law of pulsating pressure of each protective structure in the preceding chapters, the measures of vibration reduction and vibration suppression are put forward preliminarily, which can provide reference experience for relevant projects.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TV653;TV135.2

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