【作者】 张玉伦；

【导师】 刘超；

【作者基本信息】 扬州大学 ， 水利水电工程， 2010， 硕士

【摘要】 泵站工程为我国国民经济的持续发展提供了重要的保证,而且泵站作为耗能大户,提高泵站的运行效率具有重要的现实意义。前池是泵站重要的进水建筑物,其流态对水泵性能有着重要的影响。随着计算机技术的高速发展,在CFD的理论基础上,利用计算机进行数值模拟已成为研究泵站前池流态的重要方向之一,其不足就是它只是有限个离散点上的数值解,并存在一定的误差。通常情况下,还需要利用模型试验对数值计算进行验证,该方法的缺点就是需要花费大量的时间和经费。本文研究以某泵站前池为例,利用FLUENT软件并分别采用标准k-ε和RNGκ-ε紊流模型对泵站前池进行三维数值模拟,在设计流量和大流量两种工况下分别进行数值模拟,并初步比较了前池面层、中层、底层的流场。数值模拟结果表明,前池出现了脱流现象。由于前池长度足够长,总体来说,前池水流较平顺；PIV技术就是采用粒子跟踪技术来测定流场的速度及其它运动参数的。而国内的PIV技术起步比较晚,目前用于泵站进水建筑物的流场测量也较少。利用3D-PIV技术,对前池的部分空间区域的流场进行精确测量,获得了可靠的试验数据。测试的时候,需要对测量断面进行三维标定。利用相关软件对测试数据进行后处理,得出空间区域的三维流场图。基于较为准确的试验数据,比较数值模拟结果和试验结果,检验和验证所选紊流模型的可靠性和实用性。主要选择若干断面,定量比较,比较流态、流速大小。通过以上几项工作,得出了如下结论：在大流量工况下,RNGκ-ε紊流模型比较接近于试验结果；而在设计流量工况下,标准k-ε紊流模型比较接近于试验结果,也验证了在正确设置边界条件的情况下,数值模拟可以成为研究泵站前池的可靠方法。更多还原

【Abstract】 Pumping station project has provided an important guarantee for the sustainable development of national economy. Moreover, because of its great energy consuming, improving the operating efficiency of pumping station has the important practical significance. Forebay is an important intake structure of pumping station, and its flow pattern can affect the pump performance greatly.With the rapid development of computer technology, based on the the theory of CFD, the numerical simulation by using computer has become one of the important directions to do research on the flow pattern of forebay. The disadvantage is that it is only the numerical solution on a finite number of discrete points, and it exists some errors. In normal case, we need to use the model test to verify the numerical simulation which will cost plenty of time and funds.This paper takes an example of a pumping station forebay. By using FLUENT software, based on the standardκ-εand RNGκ-εturbulence model respectively, the three-dimensional numerical simulation of forebay is obtained. Furthermore, two kinds of operating conditions are added, including a large discharge and a design discharge. and the flow field of the surface layer, middle layer, bottom layer is compared preliminarily. The results of numerical simulation show that flow separation phenomenon occurs in the forebay. Because of the enough length of forebay, in general, the flow in the forebay is smooth.PIV(Particle Image Velocimetry) is to use particle tracking to measure flow speed and other motion parameters. The PIV technique starts relatively late in our country, what’s more, using PIV to measure the flow pattern of intake structure of pumping station is few. With the technique of the 3D-PIV, flow field in the part of the space of forebay is measured accurately and the reliable measurement data is acquired. In the process of measurement, three-dimensional calibration for the measuring section is needed. some relevant softwares are needed for data processing, afterwards, the three-dimensional flow field is obtained.Based on the comparatively accurate test data,the numerical simulation results and experimental results are quantitatively compared to verify and validate reliability and practicability of the selecting turbulence model. a number of measuring sections are selected to compare the flow pattern and velocity.Through the above work, this paper can conclude as follows, under a large discharge, RNGκ-εturbulence model is closer to the test results, and under a small discharge, standardκ-εturbulence model is closer to the test results, which verifies that with the correct settings in the boundary conditions, numerical simulation can also be a reliable method to study on the forebay of pumping station.更多还原