嘉兴市区河网活水调度优化研究

发布时间：2018-06-07 01:02

  本文选题：河网 + 非恒定流　； 参考：《扬州大学》2017年硕士论文

【摘要】：为了改善河流水环境,嘉兴市依托海绵城市建设,借助“引清济污”的调水手段来提升河道自净能力,加快河道的治理速度。基于现有工程设施,研究河流水动力条件,优化引排活水调度方案,对生产实践具有重要的意义。本文采用Saint-Venant方程组,建立了河网非恒定流数学模型,运用Preissmann四点加权隐格式,对方程组进行时间和空间离散,采用双松弛迭代法求解河网非恒定流。利用Sen和Garg提出的环状河网和Islam等人提出的拓扑型河网这两个算例对本文计算方法进行验证。在环状河网计算中,本文方法计算得出的各断面流量过程与Sen和Garg计算的各断面流量过程基本吻合。各断面流量过程线的计算峰值和文献中流量过程线峰值相对误差最大达到-2.67%。在拓扑型河网计算中,本文方法计算所得的流量过程和水位过程与Islam等人计算的基本吻合。各断面流量过程线的峰值和文献中流量过程线峰值相对误差最大达到1.17%,水位过程线的峰值和文献中水位过程线峰值绝对误差最大为-0.02m。计算研究表明:本文所提河网数学模型及计算方法具有模拟复杂河网明渠水流运动的能力。本文对两种泵站抽排方案,观测了嘉兴市区12个典型断面的水位值,并利用观测的水位值对河网河道糙率进行了率定。率定后的河网模型在典型断面处的计算水位值和实际测量值的绝对误差基本在±0.05m以内,表明所建立的模型适用于所选定的区域且具有较高的精度。利用上述已经率定的嘉兴市区河网非恒定流数学模型,对低水位、常水位、高水位三种工况共57种方案进行数值模拟,以河网平均流速、滞水率、南湖入流量、重点河道平均流速作为优化指标,对三种工况下的外部方案、内外部结合方案、规划方案进行分析,并分别获得了泵站引排活水优化方案。
[Abstract]:In order to improve the river water environment, Jiaxing relies on the construction of spongy city, by means of the water transfer means of "leading away the pollution" to improve the self-purification ability of the river and speed up the river course management. Based on the existing engineering facilities, it is of great significance for production practice to study the hydrodynamic conditions of rivers and optimize the scheduling scheme of diversion and drainage. In this paper, the mathematical model of unsteady flow in river network is established by using Saint-Venant equations. The equations are discretized in time and space by using Preissmann four-point weighted implicit scheme, and the unsteady flow of river network is solved by double relaxation iterative method. The calculation method of this paper is verified by two examples proposed by Sen and Garg and topological river network proposed by Islam et al. In the calculation of annular river network, the flow process of each section calculated by this method is basically consistent with that calculated by Sen and Garg. The maximum relative error between the calculated peak value of flow process line of each section and the peak value of flow process line in literature is -2.67. In the calculation of topological river network, the flow process and water level process calculated by this method are in good agreement with those calculated by Islam et al. The maximum relative error between the peak value of flow process line of each section and the peak value of flow process line in literature is 1.17, and the absolute error of water level process line and water level process line in literature is -0.02 m. The calculation results show that the mathematical model and calculation method proposed in this paper have the ability to simulate the flow movement of open channel in complex river network. In this paper, the water level values of 12 typical sections in Jiaxing urban area are observed for two pumping station drainage schemes, and the roughness of river network is determined by using the observed water level values. The absolute error between the calculated water level at the typical section and the actual measured value is within 卤0.05 m, which indicates that the established model is suitable for the selected area and has a high accuracy. Using the mathematical model of unsteady flow in Jiaxing urban area, 57 schemes of low water level, constant water level and high water level are numerically simulated. The average velocity of the key river channel as the optimization index, the external scheme, the internal and external combination scheme, the planning scheme under three working conditions are analyzed, and the optimal scheme of pumping station diversion and drainage is obtained respectively.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV213.4
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本文编号：1988953