弯曲河段污染混合区几何特征参数的实用化算法

在弯曲河段中因流线弯曲和副流的存在,使其污染混合区的几何特征参数与顺直河段有很大不同。为将顺直河段污染混合区的相关理论公式拓展应用于弯曲河段,需对其进行修正,即在与顺直河段断面形状和来流流速相同的条件下,通过地表水模型系统SMS软件模拟计算了一系列不同弯曲半径、弯曲角度的河段凹岸和凸岸排污浓度分布,分别读取不同相对允许浓度升高值时的污染混合区最大长度、最大宽度和面积,在顺直河段污染混合区几何特征参数理论公式的本构关系基础上,结合量纲—分析和曲线拟合,分别给出了弯曲河段污染混合区最大长度、最大宽度和面积的修正系数,并验证了其合理性和可行性。为弯曲河段污染混合区范围的计算提供了一种快捷、有效的实用化方法。

Practical Algorithm for Geometric Characteristic Parameters of Pollutant Mixed Zone in Bend River

Owing to the streamline curvature and secondary flow, there is a great difference between geometric characteristic parameters of pollutant mixed zone in bend river and straight river. The relevant theoretical formulas of pollutant mixed zone in the straight river need to be modified so that it can be applied to bend river. Under the same conditions of the section shape and flow velocity in straight river, a series of concentration distribution of different bend radius and bend angle in concave and convex bank emission are simulated and calculated by SMS (the software of surface water model system). The maximum length, maximum width and area in pollutant mixed zone are obtained when the increase value of allowed relative concentration are different. On the basis of the constitutive relation of the geometric characteristic parameters of pollutant mixed zone in straight river, combined with dimensionless analysis and curve fitting, this paper respectively gives the correction coefficients of the maximum length, maximum width and area in pollutant mixed zone in bend river. The rationality and feasibility are verified. Thus, it provides a quick and effective practical algorithm for calculating the range of pollutant mixed zone in bend river.