摘要
在恒定连续点源条件下,从一维流动中三维扩散方程的解析解出发,给出了顺直倾斜岸大宽度深水水库污染混合区的解析计算方法和等浓度曲面方程,分析了污染混合区断面和平面形状的变化规律;提出了采用污染混合区下游长度Ld作为特征长度定义贝克来数Pe,给出了污染混合区无量纲上、下游长度、最大宽度与最大深度及相应纵坐标和面积的计算公式及其曲线图。表明污染混合区的无量纲尺度主要取决于贝克来数,其中无量纲最大宽度和面积还与横向(垂向)和纵向扩散系数的比值λ有关、无量纲最大深度还与λ和岸坡倾角θ有关,提出了一维流动中三维扩散方程的简化条件。该解析方法和计算公式可为天然水库污染混合区的估算提供理论依据。
Under the condition of point source which is continuous and constant, and from the analytical solution for Three Dimensional Diffusion Equation of one-dimensional flows, this paper gives the analytic calculation method and the surface equation of equal concentration for pollutant mixing zone in a large width and deep reservoir with straight and gradient bank. The change laws of the cross-section and plane shape of the pollutant mixing zone are analyzed in the paper. The Peclet number （Pe） is defined by using the length of pollutant mixing zone downstream as characteristic length. Present paper also gives the calculation formulas and graph of the non-dimensional length, maximum width, maximum depth and its corresponding longitudinal coordinates and mixing zone area. The results show that the dimensionless scale is largely depended on Peclet number, and then the maximum dimensionless width and mixing zone area are interrelated to the ratio of transverse （vertical） diffusion coefficient to longitudinal diffusion coefficient （λ）, the maximum dimensionless depth are interrelated to the ratio （λ） and the bank gradient （θ）. This paper gives the simplification conditions of the three-dimensional diffusion equation in one-dimensional flows. The analytical method and calculation formula can be a reliable theoretical basis for the evaluation of the pollutant mixing zone in natural reservoirs.
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2009年第3期296-304,共9页
Chinese Journal of Hydrodynamics
关键词
环境水力学
水库
污染混合区
解析方法
倾斜岸
environmental hydraulics, reservoir, pollutant mixing zone, analytic method, gradient bank
作者简介
Email： wu_zh2008 @yahoo.com.cn. 武周虎（1959-），男，陕西岐山人，教授，硕士．
