三座店水利枢纽泄洪洞泄流三维数值模拟

发布时间：2018-07-15 13:10

【摘要】：挑流消能措施通常借助于挑流鼻坎挑流作用将高速水流挑射至空中扩散碰撞消除能量。但因泄洪洞出流流速一般较高，常常使挑坎过流面产生负压、空蚀等问题,出口水舌形态与分布难以预测，因此对泄洪洞泄流及出口流场信息的研究具有重要的现实意义。该问题的研究通常借助物理模型试验和数值模拟方法。近些年来，计算机性能的不断提升和计算流体动力学的快速发展，使得数值模拟技术已成为研究泄洪洞水力特性的重要方法。本文在总结前人研究成果的基础上，结合赤峰市三座店水利枢纽左岸泄洪冲沙洞物理模型试验结果，通过数学模型分析计算，得到以下主要成果： 1）应用ICEM软件，，对三座店水库左岸泄洪洞三维模型建立了拓扑块，并用ocrtree方法进行网格划分，使用有限体积法离散网格，采用VOF方法对自由水面进行追踪，使用可实现k-ε双方程模型闭合N-S方程；对泄洪洞泄流进行了三维数值模拟，结果表明，同体型同工况下泄洪洞出口流量、水面流态、压力分布和流速分布等水力要素的计算值与物理模型实测值吻合良好。说明数值模拟采用的模型合理，方法正确，其结果可为实际工程的设计及应用提供技术支持。 2）分析计算了差动坎和舌形坎两种挑坎方案的水流流态、流速分布及压力分布，结果表明，舌形挑坎具有较大优势。 3）对于泄流建筑物泄流及消能防冲等问题而言，物理模型试验具有不可替代的优势，数值模拟计算可作为辅助工具扩充试验数据，提供流体流动的完整信息。
[Abstract]:The energy dissipation measures usually eliminate the energy of high velocity flow through the air diffusion collision by means of the effect of jet nostrils. However, due to the high velocity of discharge in the discharge tunnel, the problems such as negative pressure and cavitation are often caused by the spillway, and the shape and distribution of the outlet water tongue are difficult to predict. Therefore, the study on the information of the discharge and the outlet flow field of the spillway is of great practical significance. This problem is usually studied by physical model test and numerical simulation. In recent years, with the continuous improvement of computer performance and the rapid development of computational fluid dynamics, numerical simulation technology has become an important method to study the hydraulic characteristics of flood discharge tunnel. On the basis of summing up the previous research results, combined with the physical model test results of the left bank flood discharge and sand flushing tunnel of Sanjiadian Water Control Project in Chifeng City, the following main results are obtained through mathematical model analysis and calculation: 1) the ICEM software is used. A topological block is established for the 3D model of the left bank of Sanjiadian Reservoir flood discharge tunnel. The ocrtree method is used to divide the grid, the finite volume method is used to discretize the grid, and the VOF method is used to track the free water surface. Using the K- 蔚 two-equation model to close the N-S equation, the 3D numerical simulation of the discharge of the flood discharge tunnel is carried out. The results show that the outlet flow rate and the water surface flow state of the discharge tunnel under the same shape and the same working condition are obtained. The calculated values of hydraulic factors such as pressure distribution and velocity distribution are in good agreement with the measured values of physical model. It is shown that the model used in numerical simulation is reasonable and the method is correct. The results can provide technical support for the design and application of practical projects. 2) the flow patterns of the two schemes of differential and tongue ridges are analyzed and calculated. The results of velocity distribution and pressure distribution show that the tongue ridges have great advantages. 3) physical model tests have irreplaceable advantages for discharging and energy dissipation and anti-scour problems of discharging buildings. Numerical simulation can be used as an auxiliary tool to expand test data and provide complete information of fluid flow.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV135.2

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