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arXiv 1612.09342math.NAcs.NA
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跳跃拼接方案用于椭圆界面问题及不可压缩纳维-斯托克斯方程

Jump splicing schemes for elliptic interface problems and the incompressible Navier-Stokes equations

University of California, Berkeley(加州大学伯克利分校)

Ben Preskill, James A. Sethian

AI总结:

本文提出一种准确计算有限差分算子的通用框架,用于处理界面处已知的不连续性。通过该方法,开发了适用于有界面不连续性的椭圆问题及具有奇异力的不可压缩纳维-斯托克斯方程的二阶准确方法。

摘要:

我们提出了一种通用框架,用于在存在已知不连续性界面的情况下准确评估有限差分算子。利用这些技术,我们开发了简单易实现、二阶准确的方法,用于具有界面不连续性的椭圆问题以及具有奇异力的不可压缩纳维-斯托克斯方程。为此,我们首先建立了一个表达式,将被评估的导数、有限差分Stencil和紧凑外推的跃迁条件联系起来。通过将界面表示为水平集函数,我们证明可以通过维度和坐标无关的法向泰勒展开构造该外推,具有任意阶的精度。我们的方法对非光滑几何具有鲁棒性,允许使用对称正定求解器求解椭圆方程,并且在3D中仅需改变有限差分Stencil即可使用。我们严格建立了该方法的收敛性,并展示了广泛的数值结果。特别是,我们证明了该方法在不可压缩纳维-斯托克斯方程中具有二阶精度。

英文摘要:

We present a general framework for accurately evaluating finite difference operators in the presence of known discontinuities across an interface. Using these techniques, we develop simple-to-implement, second-order accurate methods for elliptic problems with interfacial discontinuities and for the incompressible Navier-Stokes equations with singular forces. To do this, we first establish an expression relating the derivatives being evaluated, the finite difference stencil, and a compact extrapolation of the jump conditions. By representing the interface with a level set function, we show that this extrapolation can be constructed using dimension- and coordinate-independent normal Taylor expansions with arbitrary order of accuracy. Our method is robust to non-smooth geometry, permits the use of symmetric positive-definite solvers for elliptic equations, and also works in 3D with only a change in finite difference stencil. We rigorously establish the convergence properties of the method and present extensive numerical results. In particular, we show that our method is second-order accurate for the incompressible Navier-Stokes equations with surface tension.

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。

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