EFFECT OF ACCELERATION ON BOTTOM SHEAR STRESS IN TIDAL ESTUARIES
EFFECT OF ACCELERATION ON BOTTOM SHEAR STRESS IN TIDAL ESTUARIES
复制标题
DOI：
10.1061/(asce)0733-950x(1996)122:2(75
复制
发表时间：
1996-03
期刊：
影响因子：
--
通讯作者：
A. Kuo;Jian Shen;J. Hamrick
中科院分区：
文献类型：
--
作者：
A. Kuo;Jian Shen;J. Hamrick
通过理论分析得出了指定非定常潮汐流模型底部剪应力边界条件的公式。使用正则摄动展开式求解非定常边界层方程，求解边界附近的速度分布。当应用于数值模型计算网格的底层时，该解将底部剪应力与该层中计算的速度和加速度相关联。假设均质河口的数值实验表明，如果使用对数剖面将底部应力与速度联系起来，则计算出的底部应力的误差会随着垂直网格间距的增加而增加。使用包含修正项的公式可以显着减少该误差，并充分指定具有实际垂直网格间距范围的河口流数值模型中的边界条件。数值实验还表明，如果通过将对数分布拟合到速度分布来估计粗糙度高度和底部应力，则它们可能会偏差超过 100%。
A formulation specifying the bottom shear stress boundary condition for an unsteady, tidal flow model is derived through theoretical analysis. The unsteady boundary layer equation is solved for the velocity distribution adjacent to the boundary using a regular perturbation expansion. When applied to the bottom layer of the computation grid of a numerical model, the solution relates the bottom shear stress to the velocity and acceleration computed in that layer. Numerical experiments with a hypothetical homogeneous estuary indicate that the error in calculated bottom stress increases with vertical grid spacing if the logarithmic profile is used to relate bottom stress to velocity. The use of the formulation including the correction terms can significantly reduce this error and adequately specify the boundary condition in a numerical model of estuarine flow with a practical range of vertical grid spacing. The numerical experiments also show that, if the roughness height and bottom stress are estimated by fitting a logarithmic profile to the velocity distribution, they may be off by more than 100%.