| 摘要: |
| 开挖河床料场使河床地形突变，可导致枢纽通航水流条件发生较大变化。基于SMS软件，以Navier Stokes方程为数学模型基础，采用加权余量伽辽金有限元求解方法，对澜沧江橄榄坝枢纽工程上下游河床有无取料场的水流流场进行数值模拟，分析取料场对水流流场和枢纽通航水流条件的影响。分析表明，取料场对上下游口门区通航水流条件有一定影响，但对上游影响较小，对下游影响较为明显。具体体现为上游取料场对主流流向、口门区回流范围无大的影响，但稍许降低断面流速；下游取料场改变下游主流方向，使主流偏离引航道口门区，有效降低了口门区斜向水流流速，水流平顺，有利于船舶航行。模拟结果表明，橄榄坝枢纽河床取料对通航有利，为工程设计提供了关键的技术支撑。 |
| 关键词: 河床取料 口门区 水流； 数值模拟 模型验证； 通航条件 |
| DOI： |
| 分类号:TV135.4 |
| 基金项目:南京水利科学研究院基本科研业务费专项资金资助项目（Y115015） |
|
| Influence of riverbed material excavating field on entrance area navigation conditions |
|
LI Qian-xi1,2, HAN Chang-hai1, LI Yan-fu1, YANG Yu1
|
|
1.Key Laboratory of Navigation Structure Construction Technology of Ministry of Transport， Nanjing Hydraulic Research Institute， Nanjing;2.College of Water Conservancy and Hydropower， Hohai University， Nanjing
|
| Abstract: |
| Riverbed material excavating field may make changes in riverbed topography,which would lead to greate influence on navigable conditions. The velocity change may lead to the stop of ship sailing; the velocity direction change may give some impacts on the bank slope stability. In this article, using the fluid calculation software SMS(The Surface-Water Modeling System, created by USACE-WES and Brigham Young University, and widely used in the tidal estuary,river water flow simulation), based on the Navier-Stokes equations, a mathematical model adopting the weighted residual Galerkin finite element method is used for solving the problems. This module is to calculate unsteady flow and constant flow under the condition of water level and two-dimensional velocity universal module. The mathematical model is applied to the Ganlanba hydroelectric project which is one of the dams located on the Lancang River. Comparison analyses show that the mathematical model is in good agreement with experimental data. By simulating navigation flow conditions with presence or absence of the material excavating fields in the upstream and downstream riverbed, an analysis is made of impacts caused by riverbed material excavating field on entrance area navigation conditions. The analysis results also show that the riverbed material excavating fields have influences on navigation flow conditions of the entrance area of the approach channel, but less influences on the upstream flow patterns, and the downstream influence is more obvious. For example, the mainstream flow of the upstream does not change but the cross-section velocity is slightly lower; when the mainstream flow of the downstream changes, the mainstream flow is away from the entrance area of the approach channel, and the riverbed material excavating field can effectively reduce the oblique flow which is flowing along the entrance area of the approach channel, thus improving the flow conditions of the entrance area of the approach channel, which is favourable for the navigation. The simulation results show that the riverbed material excavating field for Ganlanba hydroelectric project is beneficial to the navigation. The research can provide a key technical support for engineering design. |
| Key words: riverbed material excavating field entrance area water flow numerical simulation physical model verification navigation conditions |
