【作者】 傅天清；

【导师】 阎庆绂；

【作者基本信息】 太原理工大学 ， 建筑与土木工程， 2003， 硕士

【摘要】 溢洪道弯道结构与水流特性，对溢洪道乃至水库枢纽工程都是十分重要的。随着大中型水利工程的不断兴建，使弯道水流特性问题日渐突出，致使其有许多问题急待解决。但因其特性复杂且影响因素较多，无论理论和试验研究还都有待深入进行。然而，到目前为止，这个领域的专题研究报道尚不多见，给溢洪道弯道水流特性研究提出了新的课题。本文针对山西省的实际情况，结合具体的工程实例，以模型试验为基础，对多种结构组合的弯道水流特性进行研究，研究的内容和得到的结论如下： 1．弯道水流基本特性研究 弯道水流不仅存在于溢洪道，还出现在其他的水利工程乃至水利工程之外的地方。基于此本文研究了以下内容： 1)弯道水流流态。研究了不同结构组合条件下，从弯道进口到出口的F_r数变化，进而得到弯道内急流和缓流特性。结果发现，弯道水流F_r数在纵向(沿流程)，横向(凹凸岸间)和垂向(水面到底板)都是变化的。说明弯道中难有单纯的急流和缓流，而是急流和缓流共存和不断变化，这与传统理论有一定的差异。 2)水面偏斜和扭曲。在所有结构组合条件下，弯道水面都有较大偏斜和扭曲，并且在弯道中部主法线方向上，基本为凹岸水面高凸岸水面低的规律。但弯道中也出现了中心线水面高两岸低的情况，甚至还有凹岸水 太原理工大学工程硕士学位论文2面低而凸岸水面高的情况。 3)流速分布研究。试验得到的纵向流速在纵向、横向和垂向都发生变化，并且在弯道中不同部位和断面的变化不尽相同，因此弯道中确实为螺旋流。但试验表明，弯道中会存在多股螺旋流，甚至有转向相反的螺旋流同时共存。 由此得到结论，弯道水流的基本特性要比理论特性复杂得多。本研究充实了弯道水流特性理论研究成果，具有一定的学术价值。2.不同结构组合弯道水流特性研究 共研究了六种组合的水流特性。 l)不同转角，曲率半径和底坡组合; 2)相同转角和曲率半径，不同底坡的组合; 3)才目同转角，曲率半径和底坡，不同边坡系数的组合; 4)有无出口斜坎的对比; 5)有无进口坎的对比; 6)不同坎高的对比。 经过比较系统的研究发现，上述诸多影响弯道水流特性因素中，转角具有最主要的作用，尤其大转角与较大底坡和泄量组合后的综合影响，会使水面偏斜和螺旋流变化更为明显，也更加不规则。目前国内尚未见到此方面的专题研究报道，所以本研究成果在溢洪道弯道水流研究方面有所创新。性几3.上下游来流条件与弯道水流特性研究 本文对弯道水流研究不限于弯道中部主法线方向的特性，而是把进口到中部直到出口的弯道整体作为研究对象。发现弯道水流特性固然主要取决于自身结构，但弯道如果脱离具体水利工程将是无意义的。既然如此，弯道上下游水流连接必然制约弯道进出口的特性，也就是说，上下游来流 太原理工大学工程硕士学位论文3实际就是弯道水流的两个边界条件，只有在这种具体条件下得到的弯道水流特性才是真实有用的。研究结果也确实表明了，弯道水流特性与上游来流条件密切相关，而弯道水流特性不但要延续到下游，也得符合水流相互连接条件。本文的这种研究方法和思路，对弯道水流特性的继续研究具有指导意义。4，弯道水流特性改善与结构优化 弯道水流偏斜和水面扭曲，对溢洪道泄流不利，设一计者往往要采取措施加以改善。本文结合实际工程，研究了弯道出口设置不同高度斜坎时，对水流特性的改善，并与不设出口斜坎特性进行比较。试验结果表明，单纯采用弯道出口设置斜坎的方法改善水流需付出较高代价，因此笔者认为，弯道水流特性的改善不能使用单一措施，应与弯道其他结构特性一并考虑，采取优化组合，使水流特性改善不致付出过高的代价。相信这种弯道水流特性研究和改善的新途径，会对溢洪道弯道设计和试验研究起到抛砖引玉的作用。5.工程实例分析 LI_I西省文峪河水库溢洪道有两个不同转角、曲率半径和底坡的弯道。本文对这两个弯道水流特性进行研究，对其在溢洪道整体特性中的地位和影响以及水流特性的改善和付出代价等作了分析，并对弯道出口有无斜坎、溢洪道中有无弯道的工程投入作了比较。分析和试验结果说明，原设计的弯道出口斜坎有利有弊，会使工程投入有较大幅度的增加，不能算作理想的一设计。如能进一步优化，必将带来更大的社会和经济效益。更多还原

【Abstract】 The structure and flow property of the spillway’s tortuous path are important to the spillway and even the key water control project. With the unceasing built of large-scale and medium-sized irrigation works, the problem of flow property of the tortuous path is becoming more and more eminent, which makes many questions need to be resolved. But the property is complex and the effective factors are much more, so that not only the theoretical research but also the experimental one needs the thorough study. But until the recent, the report on this region is very scarce, which raises a new project for the research on the flow property of the spillway’s tortuous path. According to the actual situation of the Shan’xi province, basing on the model test and combining the concrete engineering example, the article had made a research on the flow properties of the tortuous path, while the path was combined by many kinds of structures. The research contents and conclusions are as follows: 1. Basic property research on the tortuous path flow.The tortuous path flow not only exists in the spillway but also in other irrigation works and even in other places except the irrigation works. Based on the above, the article had researched the following contents: 1) Flow states of the tortuous path flow.Under the different structures’ combination, the article hadresearched the change of the Fr from the entrance to the exit of the tortuous path, and obtained the properties of the torrent and slow flow in the tortuous path. Founding that the Fr of the tortuous path flow had all changed in longitudinal (along the circuit), transverse (between the sink and convex bank) and vertical orientation (from the water surface to the bottom). This had showed that it was impossible that there had pure torrent or slow flow but the coexist and continuous change of them in the tortuous path, this had a certain difference with the traditional theory.2) Bias and turn-around of the water surface.Under the all different structures’ combination, the water surface had large bias and turn-around in the torturous path, and in the middle of the path along the longitude, there had the regularity that sink bank surface was higher than the convex bank one. But there had phenomena that the middle surface was higher than the both sides’ and even the sink bank one was lower than the convex bank one.3) Current velocity distribution research.The lengthways velocity obtained from the experiments were all changed in the longitudinal, transverse and vertical orientation. And the changes were different in different parts and sections. So it could be concluded that the flow in the tortuous path was really spiral flow, and the experiments showed that the there had many spirals and even reverse spirals coexisted in the path.According the above, the author obtained the conclusion that the basic property in the tortuous path was more complex than thetheoretical property. The research in the article will rich the achievements of the theoretical research on the flow property of the tortuous path, and has a certain academic value. 2. Flow property research in the tortuous path with the combination of different structures.The author had researched the flow properties with six kinds of combinations.1) The combination of different corners, radiuses and bottoms.2) The combination of likely corners and radiuses with different bottoms.3) The combination of alike corners, radiuses and bottoms with different border coefficients.4) The contrast between the conditions with exit incline ridge and the one without it.5) The contrast between the conditions with entrance ridge and the one without it.6) The contrast between different heights of the ridge.Through contrasting the researches in the system, the author had found that within the above influence factors, the corner was the most important one. Above all, the influence with combination of big corner, large bottom and sluice c更多还原