摘要: |
研究给出了风暴潮漫滩预报的一种半隐半显数值模式,并将其用于珠江口风暴潮漫滩的后报。该模式将风暴潮漫滩的控制方程进行半隐半显离散,使计算稳定性不受时间步长的限制;分别用共轭斜量加速Jacobi法和文中提出的简化算法求解差分方程以提高计算效率。数值模拟试验表明:该模式计算的沿岸风暴潮与天文潮耦合水位与实测水位值吻合较好,因而对漫滩位置、范围和持续时间的计算应是合理、准确的;因模式允许使用的时间步长比ADI模式允许使用的时间步长大数倍,所以计算量大大减少,漫滩预报时间显著缩短。 |
关键词: 风暴潮漫滩 半隐半显数值模式 共轭斜量加速Jacobi法 |
DOI: |
分类号: |
基金项目:国家八五攻关资助项目,85-903-03-02 |
附件 |
|
SEMI-IMPLICIT NUMERICAL MODEL FOR STORM SURGE INUNDATION WITH APPLICATION TO THE ZHUJIANG (PEARL) RIVER ESTUARY |
DU Tao,FANG Guo-hong
|
Institute of Oceanology,The Chinese Academy of Sciences,Qingdao,266071
|
Abstract: |
A semi-implicit numerical model for simulating and predicting storm inundation in coastal area is proposed and a simplified algorithm for the model’s finite difference equation and conjugate accelerate Jacobian method are described. The model uses depth-averaged governing equation which were discretized with a semi-implicit technique in such a way that the stability of the method does not depend upon the wave celerity. In this model the gradient of water surface elevation in the momentum equations and the velocity divergence in the continuity equation were discretized implicitly, but all the other terms are discretized explicitly while an Eulerian-Lagragian approach is applied to the explicit discretization of the convective terms in the momentum equations in order to eliminate the stability restriction and to reduce some artificial viscosity by simply discretizing them explicitly. The application of the simplified algorithm improves further the computational efficiency of the model.
The model, its simplified algorithm and the conjugate gradient accelerate Jacobian method are applied to simulate and hindcast the storm surge inundation in the Zhujiang (Pearl) River Estuary. Comparison between the model's computational results of the coupled water surface level (storm surge and tides) in 2 typhoon procedures and observations shows that the model is reliable and efficient and the computation for the storm surge inundation is reasonable and accurate. |
Key words: Storm surge inundation, Semi-implicit numerical model, Conjugate gradient accelerating jacobi method |