摘要
针对船舶造成的油污染问题,提出了反向追踪溢油的概念。在反向计算过程中,对流扩散方程的对流项一方面具有强烈的方向性,意味着上游信息通过对流项向下游传递;另一方面由于是逆向计算,因此计算时下游信息也需要通过对流项传递到上游。此外与顺时计算不同,扩散项在反向计算时更容易积累误差,从而使计算格式趋于不稳。针对反向计算的如上特点,我们对对流项和扩散项均采取了中心差分的处理方式。通过对两个算例(1)无界区域和(2)有界区域的实例演算,我们认为该方法无论是在开放的海域还是在封闭或半封闭海域均能取得基本令人满意的结果。
In accordance with the problem of oil pollution brought by ships, the concept of backward tracing oil spills present. In the course of backward calculation of the two-dimensional convection & diffusion equation, on one hand the advection term itself has the strong unilateral property, which means information in the upper reaches is transmitted downstream via the advection term; on the other hand, because of the opposite direction of calculation, it is essential for the information to be conveyed upstream by means of the advection term. In addition, unlike that in the forward calculation, the diffusion term in the backward calculation is prone to accumulate errors, thus renders the whole scheme unstable. Therefore, the central difference to deal with both the convectional and the diffusion term was adopted. By examining two practical examples (1) under the unlimited boundary condition, and (2) under the limited boundary condition, it was proven that the method could achieve fundamentally satisfactory not only in the open ocean but also in the close or semi-close bay.
出处
《海洋环境科学》
CAS
CSCD
北大核心
2004年第2期16-19,共4页
Marine Environmental Science
基金
中国科学院知识创新工程项目(kzcx2 202)
关键词
反向计算
对流扩散
数值耗散
backwards calculation
advection-diffusion
numerical dissipation
