arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2201.00264math.NAcs.NAphysics.comp-ph
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具有预定精度阶数和分数精化比的离散化误差估计

Estimating Discretization Error with Preset Orders of Accuracy and Fractional Refinement Ratios

Sharp Chim Yui Lo

摘要:

解决方案的验证对于建立模拟的可靠性至关重要。一个核心的挑战是找到一个准确可靠的估计的离散化误差。目前的估计方法依赖于所观察到的准确性顺序;然而,研究表明,它可能会不规则地改变或变得不确定。因此,我们提出了一种网格加密方法,它采用恒定的命令,由用户给定,称为预置订单扩展方法(POEM)。保证用户通过迭代获得最优阶数集,从而获得离散化误差的准确估计。该方法通过评估展开项的收敛性来评估估计的可靠性,这是所有网格细化方法的基础。我们证明了这些能力,沿不同的细化路径使用平流和扩散问题。POEM需要一个较低的计算成本时,细化比率较高。然而,由于共享网格点的数量减少,估计误差遭受更高的不确定性。我们规避这一点,使用分数细化比和插值之间的差异近似解(MIDAS)的方法。因此,我们可以得到一个整体估计的离散化误差较低的不确定性,在减少计算成本。

英文摘要:

Verification of solutions is crucial for establishing the reliability of simulations. A central challenge is to find an accurate and reliable estimate of the discretization error. Current approaches to this estimation rely on the observed order of accuracy; however, studies have shown that it may alter irregularly or become undefined. Therefore, we propose a grid refinement method which adopts constant orders given by the user, called the Preset Orders Expansion Method (POEM). The user is guaranteed to obtain the optimal set of orders through iterations and hence an accurate estimate of the discretization error. This method evaluates the reliability of the estimation by assessing the convergence of the expansion terms, which is fundamental for all grid refinement methods. We demonstrate these capabilities using advection and diffusion problems along different refinement paths. POEM requires a lower computational cost when the refinement ratio is higher. However, the estimated error suffers from higher uncertainty due to the reduced number of shared grid points. We circumvent this by using fractional refinement ratios and the Method of Interpolating Differences between Approximate Solutions (MIDAS). As a result, we can obtain a global estimate of the discretization error of lower uncertainty at a reduced computational cost.

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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