| 河流纵向分散系数研究 |
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| 引用本文： | 邓志强,褚君达.河流纵向分散系数研究[J].水科学进展,2001,12(2):137-142. |
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| 作者姓名： | 邓志强 褚君达 |
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| 作者单位： | 河海大学环境水利研究所, 江苏南京210098 |
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| 摘 要： | 研究了天然河流纵向分散系数理论公式及其参数的确定问题.借助于抛物型断面型态方程确定了河道垂线水深沿河宽的分布及流速分布对断面平均流速的偏离u‘的横向分布,给出了横向混合系数计算方法.在此基础上通过对Fischer的三重积分的直接求解,建立了新的天然河流纵向分散系数计算公式.这一新建立的纵向分散系数计算公式与原有的有代表性的经验公式以及26条美国河流上实测的59组资料进行了比较,比较结果表明,本文建立的纵向分散系数计算公式能给出与实测纵向分散系数最接近的预测值.与现有的其它纵向分散系数计算公式相比,本文建立的天然河流纵向分散系数公式理论上更加合理,机理上更加清楚,并且具有最小的预测误差.
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| 关 键 词： | 天然河流 纵向分散系数 横向混合系数 |
| 文章编号： | 1001-6791(2001)02-0137-06 |
| 收稿时间： | 2000-04-27 |
| 修稿时间： | 2000年4月27日 |
Longitudinal Dispersion Coefficient in Natural Rivers |
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| DENG Zhi-qiang,CHU Jun-da.Longitudinal Dispersion Coefficient in Natural Rivers[J].Advances in Water Science,2001,12(2):137-142. |
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| Authors: | DENG Zhi-qiang CHU Jun-da |
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| Institution: | Institute of Environmental Water Science, Hohai University, Nanjing 210098, China |
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| Abstract: | The paper extends a significant progress both in theory and in application of the prediction of longitudinal dispersion coefficient for natural rivers.The method is based on the hydraulic geometry relationship of stable rivers and on the assumption that the equations used in uniform-flow are still valid for local depth-averaged variables.The lateral distributions of the local flow depth and the deviation of local velocity from the cross-sectional average value are determined for straight alluvial rivers.By using the suggested transverse mixing coefficient equation and the direct integration of Fischer's triple integral,the paper presents a new theoretical equation of the longitudinal dispersion coefficient for natural rivers.The distinct feature of the new equation lies in its involvement of the transverse mixing coefficient.By the comparison with 59 sets of field data and the equations by other investigators,it is found that the equation presented in this paper predicts the longitudinal dispersion coefficient of natural rivers more accurately.Moreover,the new equation is reasonable in theory and clearer in dispersion mechanism as compared to other equations. |
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| Keywords: | natural river longitudinal dispersion coefficient lateral mixing coefficient |
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