arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1403.0140math.NAcs.NA
收藏

双涡旋非线性浅水模型的守恒形式及其数值算法

A conservation formulation and a numerical algorithm for the double-gyre nonlinear shallow-water model

University of Wyoming(怀俄明大学)

Dongyang Kuang, Long Lee

AI总结:

本文提出了一种守恒形式和数值算法,用于求解β平面上的简化浅水方程,通过常风力作用形成双涡旋环流。方法将 governing equations 转换为非线性双曲守恒律加源项,并采用二阶分数步算法求解,具有高分辨率和对粘性参数不敏感的特性。

摘要:

我们提出了一个守恒形式和一个数值算法,用于在β平面上的简化浅水方程,受恒定风力作用,导致封闭海洋盆地中形成双涡旋环流。本文的创新点在于将 governing equations 转换为非线性双曲守恒律加源项。采用二阶分数步算法求解转换后的方程。在分数步算法的第一步中,用波传播有限体积法求解齐次双曲浅水方程。所得中间解被用作第二步初始边界值问题的初始条件。因此,所提方法对粘性参数的选择不敏感,并且在罗斯比变形半径被解析的情况下,即使在粗网格上也能提供高分辨率的结果。我们讨论了每个步骤中的边界条件,当施加无滑移边界条件时。我们通过在f平面上的周期性流进行验证,该流有精确解。我们通过数值测试验证了所提算法的阶次精度。我们通过高度异常和流函数等值线来展示双涡旋模型的准稳态解,以说明封闭盆地中双涡旋环流的形成。我们的计算结果与文献中的结果高度一致。最后,我们提出一个应用,其中双涡旋模型与输运方程耦合,用于模拟封闭海洋盆地中污染物的输运。

英文摘要:

We present a conservation formulation and a numerical algorithm for the reduced-gravity shallow-water equations on a beta plane, subjected to a constant wind forcing that leads to the formation of double-gyre circulation in a closed ocean basin. The novelty of the paper is that we reformulate the governing equations into a nonlinear hyperbolic conservation law plus source terms. A second-order fractional-step algorithm is used to solve the reformulated equations. In the first step of the fractional-step algorithm, we solve the homogeneous hyperbolic shallow-water equations by the wave-propagation finite volume method. The resulting intermediate solution is then used as the initial condition for the initial-boundary value problem in the second step. As a result, the proposed method is not sensitive to the choice of viscosity and gives high-resolution results for coarse grids, as long as the Rossby deformation radius is resolved. We discuss the boundary conditions in each step, when no-slip boundary conditions are imposed to the problem. We validate the algorithm by a periodic flow on an f-plane with exact solutions. The order-of-accuracy for the proposed algorithm is tested numerically. We illustrate a quasi-steady-state solution of the double-gyre model via the height anomaly and the contour of stream function for the formation of double-gyre circulation in a closed basin. Our calculations are highly consistent with the results reported in the literature. Finally, we present an application, in which the double-gyre model is coupled with the advection equation for modeling transport of a pollutant in a closed ocean basin.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑