基于积分法和浓度矩法纵向离散系数的推导及比较  

Derivation and Comparison of Longitudinal Dispersion Coefficients Based on Integral Method and Concentration Moment Method

作　　者：郑文言 郑晓亭 沈良朵 ZHENG Wen-yan;ZHENG Xiao-ting;SHEN Liang-duo(School of Port and Transportation Engineering of Zhejiang Ocean University,Zhoushan 316022,China)

机构地区：[1]浙江海洋大学港航与交通运输工程学院,浙江舟山316022

出　　处：《浙江海洋大学学报（自然科学版）》2020年第5期429-435,共7页Journal of Zhejiang Ocean University：Natural Science

基　　金：浙江省新苗计划浙江海洋大学项目(2018R411014);浙江省教育厅项目(Y201839488);浙江舟山市科技局一般项目资助;国家自然科学基金(11602222)。

摘　　要：纵向离散系数是描述物质输移扩散的一个重要参数,其精度直接影响物质输移扩散预测结果的可靠性。本文分别基于积分公式法和浓度矩法,推导了沿水深为对数、线性和抛物线型流速分布下的纵向离散系数并对结果进行比较分析。在此基础上,采用了浓度矩法推导了随时间变化的对数流速分布情况下的纵向离散系数并对结果进行了详细分析,指出非恒定流情况下纵向离散系数不同于恒定流情况下的特征。Longitudinal dispersion coefficient is an important parameter for describing material transport and diffusion.Its accuracy directly affects the reliability of forecast results of material transport and diffusion.Based on the integral method and concentration moment method,the longitudinal dispersion coefficients of log-arithmic,linear and parabolic velocity distributions along water depth are derived and compared.On this basis,the longitudinal dispersion coefficient under logarithmic velocity distribution with time is derived by using concentration moment method,and the results are analyzed in detail.It is pointed out the traits of longitudinal dispersion coefficient under unsteady flow is different from that under constant flow.

关 键 词：纵向离散系数 离散系数 浓度矩法 积分法 非恒定流 

分 类 号：TV133[水利工程—水力学及河流动力学]