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arXiv 1810.00517math.NAcs.NA
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流体流动降阶建模中的交换误差

Commutation Error in Reduced Order Modeling of Fluid Flows

Virginia Tech(弗吉尼亚理工大学)

Birgul Koc, Muhammad Mohebujjaman, Changhong Mou, Traian Iliescu

AI总结:

本文研究了降阶建模中微分与空间滤波是否可交换,分析了拉普拉斯算子和两种降阶滤波器的交换误差,并探讨了该误差对低雷诺数下降阶建模的影响。

摘要:

对于流体流动的降阶模型(ROMs),我们理论和计算地研究微分与ROM空间滤波是否可交换,即交换误差(CE)是否非零。我们研究了拉普拉斯算子以及两种ROM滤波器(ROM投影和ROM微分滤波器)的CE。此外,当CE非零时,我们探讨其是否对通过空间滤波构建的ROMs有显著影响。作为数值测试,我们使用粘度ν=10^{-1}和ν=10^{-3}的Burgers方程以及雷诺数Re=1和Re=100下的二维圆柱后方流动。我们的研究显示:(i)CE存在,(ii)CE对低雷诺数下的ROM开发有显著影响,但对高雷诺数影响不大。

英文摘要:

For reduced order models (ROMs) of fluid flows, we investigate theoretically and computationally whether differentiation and ROM spatial filtering commute, i.e., whether the commutation error (CE) is nonzero. We study the CE for the Laplacian and two ROM filters: the ROM projection and the ROM differential filter. Furthermore, when the CE is nonzero, we investigate whether it has any significant effect on ROMs that are constructed by using spatial filtering. As numerical tests, we use the Burgers equation with viscosities $ν=10^{-1}$ and $ν=10^{-3}$ and a 2D flow past a circular cylinder at Reynolds numbers $Re=1$ and $Re=100$. Our investigation shows that: (i) the CE exists, and (ii) the CE has a significant effect on ROM development for low Reynolds numbers, but not so much for higher Reynolds numbers.

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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