渐扩折坡型消力池水跃特性研究

发布时间：2018-04-25 08:26

本文选题：底流消能 + 渐扩折坡消力池　；参考：《长江科学院》2016年硕士论文

【摘要】：经由建筑物下泄的水流往往具有较高的流速,对下游河床具有明显的破坏能力。消能防冲是泄水建筑物,尤其是高水头、大流量泄水建筑物设计要解决的主要问题。常用的消能方式可按高速主流的位置与状态分为底流水跃消能、挑流消能、面流消能等几类,由于底流消能消能效果十分显著,适用于高、中、低水头各类泄水建筑物和各种地基条件,作为一种基本的消能型式,在我国获得了广泛应用。消力池的型式一般可分为平底式和斜坡式两大类,可根据地形、地质和水力条件,通过技术经济综合比较选定。渐扩折坡消力池能较好的适应工程实际需要,渐扩体型和折坡水跃使得此类消力池消能效果良好,并能适应下游水位变化。与常规的矩形消力池相比,具有消能效果良好、保护下游边坡、缩短消力池长度等优点。在实际工程中,渐扩折坡消力池已有了较为广泛的应用,如布伦口水电站、喜河水电站等,而对渐扩折坡消力池水跃公式的理论研究较少。本文以实际工程为研究对象,通过水工模型试验,对不同工况下该型消力池的水跃流态,及跃长,跃后水深等水跃特征进行了研究。首先,就物理模型试验结果结合已有经验公式,分析对比了在相同来流条件下,等宽平底型,等宽折坡型,渐扩折坡型消力池的计算跃后共轭水深。其次,在物理模型试验的基础上,采用标准κ-ε紊流模型结合VOF多相流模型,建立了消力池段的三维数值模型,对扩散折坡水跃的水跃特征参数及流速分布等进行了研究。数值模拟计算结果所得的水跃位置,跃后水深,旋滚长度值等与物理模型试验结果有较好的一致性。在此基础上,通过数值模拟研究比较了渐扩段扩散角度对消力池水力特性的影响。
[Abstract]:The flow through the building often has high velocity of flow, which has obvious damage ability to the downstream riverbed. Energy dissipation and anti-scour are the main problems to be solved in the design of draining structures, especially those with high water head and large discharge. According to the position and state of high speed mainstream energy dissipation, the commonly used energy dissipation methods can be divided into following categories: bottom flow jump energy dissipation, jet flow energy dissipation, surface flow energy dissipation, etc. Due to the effect of bottom flow energy dissipation is very remarkable, it is suitable for high, medium, etc. As a basic type of energy dissipation, low-head structures and various foundation conditions have been widely used in China. The type of stilling pool can be divided into two types: flat bottom type and slope type, which can be selected according to the topography, geology and hydraulic conditions through the comprehensive comparison of technology and economy. The gradual expansion slope stilling pool can better meet the practical needs of engineering. The gradual expansion and slope hydraulic jump make the energy dissipation effect of this kind of stilling pool good and adapt to the change of downstream water level. Compared with the conventional rectangular stilling pool, it has the advantages of good energy dissipation effect, protecting the downstream slope and shortening the length of the stilling pool. In the practical engineering, the gradually expanding slope stilling pool has been widely used, such as Brancou Hydropower Station, Xihe Hydropower Station and so on, but the theoretical research on the hydrodynamic jump formula of the gradually expanding slope stilling pool is less. Taking the actual engineering as the research object, the hydraulic jump characteristics of this type of stilling tank under different working conditions, such as jump length, water depth and so on, are studied by hydraulic model test. Firstly, based on the results of physical model tests and empirical formulas, the conjugate water depth of equal-width flat-bottom type, equal-width break slope type and involute slope type stilling pool is analyzed and compared under the same conditions. Secondly, based on the physical model test, the standard 魏-蔚 turbulence model combined with the VOF multiphase flow model is used to establish the three-dimensional numerical model of the stilling pool, and the characteristic parameters and velocity distribution of the hydraulic jump are studied. The results obtained from the numerical simulation are in good agreement with the physical model test results, such as the position of the jump, the depth of the water after the jump and the value of the rolling length. On this basis, the influence of diffusion angle on hydrodynamic characteristics of stilling tank is compared by numerical simulation.
【学位授予单位】：长江科学院
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TV653;TV135.2

【参考文献】