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 2107.02072math.NAcs.NA
收藏

旋转浅水波方程的选择性衰减保结构离散

Selective decay for the rotating shallow-water equations with a structure-preserving discretization

Rüdiger Brecht, Werner Bauer, Alexander Bihlo, François Gay-Balmaz, Scott MacLachlan

摘要:

天气和气候的数值模式严重依赖于双曲守恒律系统积分器的长期稳定性。虽然这种稳定性通常是从(物理或数值)耗散项获得的,但这种模拟的物理保真度也取决于适当地保持系统的守恒量,如能量。为了解决这个明显的矛盾,我们开发了一个变分积分的浅水方程,节约能源,但耗散潜在的拟能。我们的方法遵循连续选择性衰变框架[F. Gay-Balmaz和D.霍尔姆.无粘流体中Casimir耗散的选择性衰减。Nonlinearity,26(2):495,2013],这使得能够耗散否则守恒的量,同时守恒总能量。我们结合变分离散化方法[D. Pavlov,P. Mullen,Y. Tong、黄毛菊E. Kanso,J. Marsden和M.德斯布伦不可压缩流体的保结构离散化。Physica D:Nonlinear Phenomena,240(6):443-458,2011]以获得离散的选择性衰减框架。这是适用于浅水方程,无论是在平面上和球面上,消散的潜在拟能。由此产生的计划显着提高了质量的近似解,使长期的积分进行。

英文摘要:

Numerical models of weather and climate critically depend on long-term stability of integrators for systems of hyperbolic conservation laws. While such stability is often obtained from (physical or numerical) dissipation terms, physical fidelity of such simulations also depends on properly preserving conserved quantities, such as energy, of the system. To address this apparent paradox, we develop a variational integrator for the shallow water equations that conserves energy, but dissipates potential enstrophy. Our approach follows the continuous selective decay framework [F. Gay-Balmaz and D. Holm. Selective decay by Casimir dissipation in inviscid fluids. Nonlinearity, 26(2):495, 2013], which enables dissipating an otherwise conserved quantity while conserving the total energy. We use this in combination with the variational discretization method [D. Pavlov, P. Mullen, Y. Tong, E. Kanso, J. Marsden and M. Desbrun. Structure-preserving discretization of incompressible fluids. Physica D: Nonlinear Phenomena, 240(6):443-458, 2011] to obtain a discrete selective decay framework. This is applied to the shallow water equations, both in the plane and on the sphere, to dissipate the potential enstrophy. The resulting scheme significantly improves the quality of the approximate solutions, enabling long-term integrations to be carried out.

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。

↑