厦门港湾内潮流的有限元分析

THE DEFINITE ELEMENTAL ANALYSIS OF CURRENTS IN THE XIAMEN HARBOUR

近几年来,有限元法广泛地应用于解垂直积分平均方程,如潮汐、潮流和近岸环流等。对岸线曲折的港湾来说,有限元网格比有限差分网格灵活得多。但是,由于港湾内地形复杂,水域宽窄变化很大,必须有较高的空间分辨度,即计算网格的空间步长必定很小。通常用的显式时间步进积分法,最大的时间步长受Courant稳定性判据限制.

Based on the mean equation groups of standard vertical integration,byommitting acceralation of the advection,horizontal diffusion,Coriolis forceand wind stress,linearizing bottom friction terms and mass conservationequations,assuming the periodic flow inside an estuary and harbour,theauthor develops the current velocity and water level as Fourier Series,calculates its coefficients by the numerical approach of definite elementand the field of M2 component in the West Harbour of Xiamen by anumerical model.The results are in good agreement with the observedvalues.This model is used to analyze quantitatively the change of currentfields in the West Harbour of Xiamen after the construction of theYuandang Causeway.