| 武周虎,武文,路成刚.河流混合污染物浓度二维移流扩散方程的解析计算及其简化计算的条件Ⅰ：顺直宽河流不考虑边界反射[J].水利学报,2009,40(8): |
| 河流混合污染物浓度二维移流扩散方程的解析计算及其简化计算的条件Ⅰ：顺直宽河流不考虑边界反射 |
| Analytical calculation of the two dimensional advection diffusion equationfor pollutant mixing in river and conditions for simplificationⅠ.Wide straight river without boundary reflection |
| |
| DOI： |
| 中文关键词: 污染混合区 二维解析方法 无量纲诺莫图 移流扩散方程 简化条件 非保守物质 |
| 英文关键词: pollutant mixing zone 2-D analytic method dimensionless nomograph advection diffusion equation simplification condition non conservative matte |
| 基金项目: |
|
| 摘要点击次数: 3064 |
| 全文下载次数: 755 |
| 中文摘要: |
| 在恒定连续点源条件下，从移流扩散方程的二维解析解出发，给出了顺直宽河渠无边界反射情况下，污染混合区的二维解析计算方法和等浓度曲线方程，分析了污染混合区的形状变化规律。以简化二维移流扩散条件下的污染混合区长度为特征长度L、流速U和纵向扩散系数E-L，定义了贝克来数Pe=UL/E-L，给出了污染混合区无量纲上、下游长度、最大宽度及相应纵坐标和面积的试算公式及诺莫图。结果表明，污染混合区的无量纲长度主要取决于贝克来数，而无量纲最大宽度和面积既取决于贝克来数也与横向与纵向扩散系数的比值λy有关。在此基础上，给出了非保守物质污染混合区的修正计算方法，以及保守与非保守物质的计算分区图。系统地提出了二维移流扩散方程的简化计算条件。 |
| 英文摘要: |
| Based on the 2-D analytic solution of the advection diffusion equation, a 2-D analytic computational method for the pollutant mixing zone and iso concentration line equation for wide straight rivers under the condition of constant continuous point source and without boundary reflection was established. The variation of the shape of pollutant mixing zone was analyzed. The Peclet number (Pe=UL/E-L) was defined using the largest lenght L, flow velocity U, longitudinal diffusion coefficient E-L of the pollution mixing zone as the characteristic parameters, and the calculation formulas and nomograph of the dimensionless lengths, maximum width and areas of the pollutant mixing zone were given. The results show that the dimensionless lengths are mainly dependent on Pe, and the maximum dimensionless width and area are both dependent on Pe and λy(the ratio of transverse diffusion to coefficient to lognitudinal diffusion coefficient). On this basis, the conditions for simplifying the advection diffusion equation is given, the modified calculating method of non conservative matter pollutant mixing zone and the critical curve for distinguishing conservative and non conservative matter are proposed. |
|
查看全文
查看/发表评论 下载PDF阅读器 |
| 关闭 |