【摘要】 使用Casulli等(2000)的数值方法建立了基于正交非结构网格的U型渠道的三维近岸正压水动力数值模型,检验了模型使用ELM(Eulerian-Lagrangian Method)方法处理平流项时,物理流场的定义对模拟结果的作用。数值试验和结果分析说明,使用ELM方法计算平流项所需的物理流场对计算结果影响明显,而目前常用的两种物理流场定义方法都存在一定不足——水位计算值对流速变化的反映不灵敏或者会产生小扰动等。针对常用物理流场定义方法的不足之处,作者在Casulli方法的基础上利用对多边形切向流速分量进行平均的方法改进了物理流场定义,抑制了小扰动。更多还原

【Abstract】 A 3-D coastal barotropic hydrodynamic numerical model in a U-channel covered with an orthogonal unstructured gird was established using the numerical scheme of Casulli(2000).The effects of two current velocity definitions of physical current field for the advection term calculated by the Eulerian-Lagrangian Method(ELM) were examined.The numerical experiments and the results analysis showed that the results were obviously influenced by the definition of the physical current field used by ELM.Some disadvantages exist using the two common methods,such as insensitive feeding back between the velocity and elevation and existence of small oscillation.A new physical current field definition based on Casulli’s scheme was proposed to inhibit the small oscillation in the orthogonal unstructured grid numerical model.更多还原