基于无结构网格有限体积法的风暴潮数值预报模式

A numerical storm surge model based on unstructured meshes and finite volume method

基于无结构三角单元网格和有限体积法,建立了一个高精度高分辨率的风暴潮二维数值预报模式。该模式采用对岸线有较强拟合能力的无结构网格对求解区域进行离散,采用藤田公式和宫崎正卫风场模式模拟气压场和风场。由于台风暴潮在近岸地区受底部地形的影响,可能引起非线性较强的波动,从而产生陡度大的波面,因此模式中利用Roe的通量函数给出守恒方程的无粘性通量。针对复杂的海底地形,对模式专门进行了通量梯度项与源项的平衡。应用此模型模拟和预报珠江口地区的风暴潮增水,取得了较满意的结果。

A high-precision, high-resolution, two-dimensional numerical storm surge model is built based on the unstructured meshes and finite volume method. Unstructured meshes, which can fit bank better, are used to separate the region. Fujita formula and Veno Takeo formula are used to simulate pressure and wind separately. Because the influence of bottom topography in coastal areas can cause nonlinear oscillation, Roe＇s flux function is used in conservation equations. The balance between flux gradients and source terms is done to handle the irregular bottom topography. Good results have been obtained by using the model to simulate and forecast the water level set-up in the Zhujiang River estuary.