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arXiv 2512.04574physics.flu-dyncs.NAmath.NA
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显式亚格子模型能否增强隐式大涡模拟?从高阶求解器角度看

Can Explicit Subgrid Models Enhance Implicit LES Simulations? A Very High-Order Solver Perspective

ETSIAE-UPM - School of Aeronautics, Universidad Politécnica de Madrid(马德里理工大学航空工程学院);Center for Computational Simulation, Universidad Politécnica de Madrid(马德里理工大学计算模拟中心);Simerics Inc(Simerics公司);Faculty of Mechanical Engineering, Technische Universiteit Delft(代尔夫特理工大学机械工程学院);Barcelona Supercomputing Center(巴塞罗那超级计算中心)

Gonzalo Rubio, Gerasimos Ntoukas, Miguel Chávez-Módena, Oscar Mariño, Bernat Font, Oriol Lehmkuhl, Eusebio Valero, Esteban Ferrer

AI总结:

研究高阶DG方法在湍流模拟中,显式Vreman SGS建模与数值耗散相互作用,通过三维泰勒 - 格林涡评估相关指标,明确其有用性依赖多种因素及不同分辨率下的表现,为高阶DG湍流模拟选耗散机制提供指导。

摘要:

高阶间断伽辽金(DG)方法在湍流模拟中精度优异,在面向GPU的架构上愈发有吸引力。然而,高阶欠分辨率模拟仍对数值耗散和模型耗散间的平衡敏感。本文研究在DGSEM框架中显式Vreman亚格子尺度(SGS)建模如何与分裂形式稳定化及黎曼求解器的耗散相互作用。利用Re = 1600的三维泰勒 - 格林涡及无粘极限情况,评估动能耗散、谱精度和稳定性。结果表明显式SGS建模的有用性强烈依赖分辨率、多项式阶数和已有数值耗散。在充分解析情况下,Vreman建模未提高精度;在类似自由度下,低阶模拟在最小解析尺度附近引入更强阻尼,高阶模拟保留更多谱内容但在耗散不足时更易出现高波数能量积累。在更强欠分辨率下,弱SGS贡献可控制积累,过度SGS耗散会降低中间尺度。这些结果确定了显式SGS建模有益、中性或有害的情况,为适合现代GPU架构的高阶DG湍流模拟中选择耗散机制提供了实用指导。

英文摘要:

High-order discontinuous Galerkin (DG) methods offer excellent accuracy for turbulent-flow simulations and are increasingly attractive on GPU-oriented architectures, where high polynomial orders can improve arithmetic intensity. However, very high-order under-resolved simulations remain sensitive to the balance between numerical and modeled dissipation. We investigate how explicit Vreman subgrid-scale (SGS) modeling interacts with dissipation from split-form stabilization and Riemann solvers in a DGSEM framework. Using the three-dimensional Taylor-Green vortex at Re=1600 and in the inviscid limit, we assess kinetic-energy dissipation, spectral accuracy, and stability across well-resolved, under-resolved viscous, and strongly under-resolved regimes, comparing lower- and very high-order configurations at similar degrees of freedom. The usefulness of explicit SGS modeling depends strongly on resolution, polynomial order, and the numerical dissipation already present. In the well-resolved cases considered, Vreman modeling does not improve accuracy because its active wavenumber range overlaps with the scheme's inherent dissipation. At similar degrees of freedom, lower-order simulations introduce stronger damping near the smallest resolved scales, whereas very high-order simulations preserve more spectral content but are more susceptible to high-wavenumber energy accumulation when dissipation is insufficient. Under stronger under-resolution, a weak SGS contribution can control this accumulation, while excessive SGS dissipation degrades intermediate scales. These results identify regimes in which explicit SGS modeling is beneficial, neutral, or detrimental, and provide practical guidance for selecting dissipation mechanisms in very high-order DG turbulence simulations suited to modern GPU architectures.

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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