宽浅分汊河道航电枢纽布置及水力学研究

发布时间：2018-05-29 00:46

本文选题：分汊河道 + 航电枢纽　；参考：《重庆交通大学》2017年硕士论文

【摘要】：分汊河道是天然河流中一种常见的河型,其水流流态十分复杂,在分汊口处,水流由于弯曲产生离心作用形成水面横向比降以及环流、流线方向改变剧烈时,支汊进口段还可能形成分离区。交汇处的水流则产生顶托作用,发生紊动掺混,形成旋涡,同时,支汊水流受河岸边界条件的限制,在交汇口下游附近也易形成分离区,产生断面环流。所以,与单一河道相比,在分汊河道上布置航电枢纽更为困难,而规范中也未针对宽浅分汊河道航电枢纽的布置给出详细的规定,因此,分析分汊河道的水流特性,研究分汊河道航电枢纽的布置具有重要的现实意义及应用价值。航电枢纽工程中各类水流条件的研究方法主要有理论分析、物理模型试验研究以及数学模拟研究等。采用物理模型试验可以模拟枢纽复杂的边界条件,但是受试验场地限制,模拟河道范围有限。而若能建立枢纽二维水流数学模型,作为物理模型的补充,则可以在扩大河段研究范围的同时,缩短研究周期。然而,目前对枢纽河段水流条件的数值模拟中,通常将枢纽复杂的布置予以简化导致计算精度难以满足要求,同时模型通常仅能模拟闸门关闭和敞泄两种状态,难以模拟枢纽实际运行中各种灵活的调度规则。所以,提高枢纽数学模型的计算准确度以及扩大模型的适用范围显得尤为重要。本文以虎渡溪航电枢纽工程为依托,通过收集水文、泥沙及地质资料,采用数值模拟与物理模型试验相结合方法,对分汊河道的航电枢纽布置、水流特性以及船闸引航道口门区的通航水流条件进行研究。研究内容主要包括:(1)通过收集岷江彭山水文站相关资料结合水文泥沙特性对虎渡溪航电枢纽的选址与布置方案进行研究,结合同类型枢纽布置,总结分汊河道航电枢纽布置的一般要求。(2)针对目前枢纽二维水流数值模拟存在的难以模拟枢纽复杂边界条件以及闸门灵活调度的问题,提出了对枢纽进行分解模拟的方法,提高枢纽数值模拟的准确度及可信度。(3)采用物理模型和数学模型相结合的方法,对分汊河道下游沙河坝岛的防洪问题和下引航道口门区通航水流条件进行研究,提出在下游布置分洪道还原天然分汊河道分流比方法解决下游河道防洪问题,并对设置分洪道对下引航道口门区通航水流条件的影响进行了研究。
[Abstract]:Branching channel is a common type of river in natural rivers, and its water flow pattern is very complicated. At the bifurcation point, the centrifugal effect of water flow due to bending results in the lateral drop of water surface and the circulation, and the direction of flow line changes sharply. The branch inlet may also form a separation zone. On the other hand, the flow at the junction produces topping, turbulent mixing and vortex formation. At the same time, the branch flow is restricted by the boundary condition of the river bank, and the separation area is easily formed near the lower reaches of the junction, resulting in the cross section circulation. So, compared with the single channel, it is more difficult to arrange the avionics hub on the branching channel, and the layout of the navigation and power junction of the wide and shallow branching channel is not specified in the code. Therefore, the flow characteristics of the branching channel are analyzed. It is of great practical significance and application value to study the arrangement of navigation and power junction in branching channel. The research methods of various kinds of flow conditions in the navigation and power hub project are mainly theoretical analysis, physical model test and mathematical simulation. The complex boundary conditions can be simulated by physical model test, but the range of simulated river is limited by the limitation of test site. If the two-dimensional flow mathematical model of the junction can be established as a supplement to the physical model, the research period can be shortened while the study range of the river reaches is enlarged. However, at present, in the numerical simulation of the flow conditions of the river reach of the hub, the complicated arrangement of the hub is usually simplified to make the calculation accuracy difficult to meet the requirements. At the same time, the model can only simulate the two states of gate closure and open discharge. It is difficult to simulate all kinds of flexible scheduling rules in the actual operation of the hub. Therefore, it is very important to improve the calculation accuracy of the mathematical model and expand the application range of the model. In this paper, based on the Huduxi Navigation and Power Project, by collecting hydrological, sediment and geological data and combining the numerical simulation with the physical model test, the arrangement of the aviation-power hub of the branching channel is made. The characteristics of water flow and the navigable flow conditions in the entrance area of approach channel of ship lock are studied. The main research contents include: (1) by collecting relevant data of Pengshan Hydrologic Station of Minjiang River combined with hydrological and sediment characteristics, the location and layout scheme of Huduxi Navigation and Power Station is studied, and the layout of the same type of hub is also studied. This paper summarizes the general requirements for layout of navigation and power junction in branching channel. Aiming at the problems of complex boundary conditions and flexible operation of sluice gate, which are difficult to simulate in numerical simulation of 2D flow in the junction at present, a method of decomposing and simulating the junction is put forward. In order to improve the accuracy and reliability of the numerical simulation of the junction, the method of combining physical and mathematical models is used to study the flood control problems of Shaheba Island in the lower reaches of the branching channel and the navigable flow conditions in the entrance area of the lower approach channel. The method of reducing the distribution ratio of natural branching channel in the downstream is put forward to solve the problem of flood control in the downstream channel, and the influence of setting the diversion channel on the navigable flow condition in the entrance area of the lower approach channel is studied.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV61;TV135.1

【参考文献】