低佛氏数消力池三维紊流数值模拟

发布时间：2019-06-10 10:04

【摘要】：低佛氏数水跃常存在低水头水利工程中，其特点是没有明显的波状水跃，消能效率比较低，不仅影响了水利工程的正常运行，而且对河床侵蚀比较严重。因此如何优化消能工的消能型式是低水头水利工程的亟需解决的问题之一。结合工程实例作为低水头消能工做数值模拟研究，首先对国内外的研究进行了回顾，之后为了研究如何提高消能效率，本文提出了一种新型的悬栅消能工，采用几何重构的VOF法和k-ε紊流模型相耦合的计算模型来对提出的多种新型悬栅消能工的水气两相流进行数值模拟，并将它们与传统的SAF型消能工在消能效果、流态分布等方面进行比较分析，从中获得消能效果相对较好的新型悬栅消能工。悬栅消能工丰富了底流消力池辅助消能工的选择型式。悬栅的设置位置、悬置高度、栅条与陡坡夹角是影响悬栅消能主要三个因素，所以本文对这三个方面进行优化设计来提高消能效率。根据池长缩短的情况下，将其与传统消能工进行消能防冲比较分析，对实际工程的建设提供了理论基础和参考条件。模拟研究表明：悬栅消能工能够较好的应用于底流消力池，，在低佛氏数的水流条件下，相比较传统型，新型悬栅消能工有较好的消能效果，而且新型悬栅消能工结构简单，施工方便，在含沙量比较大的低水头工程可以推广使用。
[Abstract]:Low Fahrenheit water jump often exists in low head water conservancy project, which is characterized by no obvious wavy water jump and low energy dissipation efficiency, which not only affects the normal operation of water conservancy project, but also seriously erodes the river bed. Therefore, how to optimize the energy dissipation type of energy dissipators is one of the urgent problems to be solved in low head water conservancy projects. Combined with an engineering example, the numerical simulation of low head energy dissipator is carried out. Firstly, the research at home and abroad is reviewed. Then, in order to study how to improve the energy dissipation efficiency, a new type of suspended grid energy dissipator is proposed in this paper. The numerical simulation of water-gas two-phase flow of various new suspended gate energy dissipators is carried out by using the coupled calculation model of geometric reconstruction VOF method and k-蔚 turbulence model, and they are compared with the traditional SAF type energy dissipator. The flow pattern distribution is compared and analyzed, and a new type of suspended grid energy dissipator with relatively good energy dissipation effect is obtained. The suspended grid energy dissipator enriches the selection type of the auxiliary energy dissipator in the bottom flow stilling pool. The setting position, height and angle between the grid and the steep slope are the three main factors that affect the energy dissipation of the suspended grid, so this paper optimizes the design of these three aspects to improve the energy dissipation efficiency. According to the condition of shortening the pool length, the energy dissipation and scour prevention of the traditional energy dissipator is compared and analyzed, which provides the theoretical basis and reference conditions for the construction of the actual project. The simulation results show that the suspended grid energy dissipator can be well applied to the bottom flow stilling pool. Under the condition of low Fahrenheit number, compared with the traditional type, the new suspended grid energy dissipator has better energy dissipation effect, and the structure of the new suspended grid energy dissipator is simple. The construction is convenient and can be popularized in the low head project with large sediment concentration.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV653;TV135.2

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