受潮汐影响的河道水面线数值分析

Numerical analysis of river flow profile affected by tide fluctuation

本文采用四点加权隐式差分格式应用牛顿－拉普逊迭代法，计算了受潮汐影响的 河道的洪水过程．计算中提出了断面概化面积与实际断面积相等的原则；并对差分格 式中的加权系数ａ值进行优化，得出ａ在（０．５，０．７）内耿值收敛快、精度高、稳 定性好，而且对时间步长的选择要求可以放松，节省了计算时间，计算结果与原型观测资料相吻合．

A Finite Difference Method with four points weighted implicit scheme and Newton-Raphson iteration method are introduced to complete the flood routing in the tidal river. The problems related to normalization of cross-sectional area and optimization of weighting factor a are discussed and a = 0.5-0.7 is suggested. With such a a,high accuracy,stable and convergence results and flexible time step will be expected. The computational example of a tidal river in Liaoning Province shows the good agreement with the measuring data on prototype.