浅水方程模拟中确定糙率的回归系数法

基于水流模拟本身就是模拟模型回归求真(即实体原型)过程的认识,从模拟模型和实体原型之间的相关关系出发,应用统计学中的线性回归分析方法,通过回归系数建立了模型与原型糙率系数之间的关系式,提出了二维浅水方程模拟中糙率确定的回归系数法。数值试验表明,该方法并不依赖于糙率系数的初值,具有稳定性好、收敛速度快的特点;对磨刀门水道水流的数值模拟应用显示,该方法能有效地改善模拟计算的精度,具有较好的适应能力,简便实用,为二维浅水流动模拟计算时率定糙率系数提供了一种有效途径。

A regression coefficient method for calibrating Manning's coefficients in shallow water flow modeling

Based on the cognition that numerical flow modeling is a regression process to prototype, from the correlation between model and prototype, a linear formulation that relates model’s and prototype’s Manning’s roughness coefficients(Manning’s n) is derived and a regression coefficient method for calibrating Manning’s n in shallow water equations is presented. Numerical tests show that the method does not only rely on the initial value of Manning’s n, but also has the attributes of good stability and fast convergence. Application to the complex flow simulation for the Modaomen channel indicates that the present method could improve the modeling precision, and has good adaptive, simple and practical abilities as well. It provides an effective way to determine Manning’s n in shallow water equations.