中小型泵站进水前池入水口水力特性数值模拟研究

发布时间：2018-05-07 13:11

本文选题：前池入水口 + 三维湍流　；参考：《扬州大学》2014年硕士论文

【摘要】：泵站入水口是水体流进泵站的第一道关口,具有稳定水流、保证泵站进水稳定性等作用,尤其对稳定泵站进水池水流和提高泵站运营效率有着非常重要的意义。在泵站进水选择形式上,正向进水无疑是最好的选择方式。但泵站多数建于河道岸边,这就意味着河道水体要经过侧向入水口而进入泵站。所以侧向入水方式在中小型泵站的建造中运用很普遍。本文以大型计算流体力学软件CFX为平台,运用三维紊流数值计算技术,对泵站前池入水口进行全面系统的研究分析,揭示进水前池入水口对入水口附近河道水体及进水池内水力特农特岗的影响,并做优化模型研究。采用RNGk-ε湍流模型对中小型泵站前池入水口进行三维湍流数值模拟研究,预演入水口的基本模型及基本流态。定性分析前池入水口对入水口附近河道水体及进水池内水力特性的影响。对比分析不同入水口深宽比及入水口角度等因素对水力特性的影响,重点分析水体流经入水口后在进水池内达到水流平稳的长度与入水口形式的关系。通过前池入水口不同深宽比和不同角度的研究,并且与基本流态特征进行对比,阐述深宽比和角度对入水口附近河道水体和泵站进水前池内水体流动的影响。结合模拟结果中的底层、中层、表层流线图和流速分布图,分析深宽比和角度对入水口水力特性影响的规律及影响进水池水体紊动的长度,总结出前池入水口模型中较为合适的深宽比和最佳角度。结合工程实际,对建于河道较窄及盲肠河道处的入水口进行数值模拟研究,得出其影响泵站进水前池水流波动长度的范围。通过数值计算分析前池入水口对河道影响的结果,针对河道水体回流流进入水口的情况,进行改善入水口形式的水力优化。本文建立八字口形式和喇叭口形式的入水口模型,并模拟、分析其水力特性。结果表明喇叭口形式的入水口形式更有利于水流的稳定。
[Abstract]:The inlet of pump station is the first gate of water flow into pump station. It has the function of stabilizing the flow of water and ensuring the stability of the inlet water of the pump station. Especially, it is of great significance to stabilize the water flow into the pool of the pump station and to improve the operation efficiency of the pump station. In pumping station water selection form, forward water is undoubtedly the best choice. But most of the pumping stations are built on the banks of the river, which means that the river water enters the pumping station through the lateral inlet. So the lateral approach is widely used in the construction of small and medium pumping stations. Based on the large-scale computational fluid dynamics software CFX and using the three-dimensional turbulent numerical calculation technology, this paper makes a comprehensive and systematic study and analysis on the inlet of the front pool of the pump station. The influence of the inlet of the forebay on the water body of the river near the inlet and the hydraulic special post in the inlet pool was revealed and the optimization model was studied. RNGk- 蔚 turbulence model is used to simulate the three dimensional turbulent flow at the inlet of the small and medium-sized pumping station. The basic model and the basic flow state of the inlet are previewed. The influence of the inlet of the front pool on the hydraulic characteristics of the channel water and the inlet pool near the inlet is analyzed qualitatively. The effects of different ratio of depth to width of inlet and angle of inlet on hydraulic characteristics were analyzed, and the relationship between the steady length of water flow in the inlet pool and the form of inlet was analyzed. Based on the study of different aspect ratios and angles of the inlet of the forebay and the comparison with the basic flow characteristics, the effects of the ratio of depth to width and the angle on the flow in the water body of the river near the inlet and the inlet of the pump station are discussed. Combined with the bottom, middle and surface streamlines of the simulation results and the velocity distribution map, the influence of depth to width ratio and angle on the characteristics of the inlet water force and the length of the turbulence in the inlet water body are analyzed. The proper ratio of depth to width and the optimum angle in the model of the inlet of the front pool are summarized. Based on the engineering practice, a numerical simulation of the inlet in the narrow channel and the caecum channel is carried out, and the range of its influence on the water flow fluctuation length in the inlet forebay of the pumping station is obtained. According to the results of numerical calculation and analysis of the influence of the inlet of the forebay on the channel, the hydraulic optimization of the form of the inlet is carried out in view of the situation of the reflux flow into the inlet of the river. In this paper, the water inlet models of eight mouth and bell mouth are established and simulated, and their hydraulic characteristics are analyzed. The results show that the orifice is more favorable to the stability of water flow.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV135

【参考文献】