2018/05/06 by Moritz Linkmann, Michele Buzzicotti, Luca Biferale · 19 citations
Earth and Planetary Sciences · Engineering · Physics and Astronomy · #Cauchy stress tensor #Fluid Dynamics and Turbulent Flows #Inertial frame of reference #Multifractal system #Oceanographic and Atmospheric Processes #Range (aeronautics) #Scaling #Series (stratigraphy) #Solar and Space Plasma Dynamics #Tensor (intrinsic definition) #Turbulence #physics.flu-dyn
paper · pdf · open access · doi:10.1080/14685248.2018.1462497
published in Journal of Turbulence 19(6), 493-527 (Taylor & Francis) · Journal of Turbulence (2018)
openalex publication_date 2018/05/06 · arxiv created 2018/05/07 · arxiv updated 2018/05/08 · openalex created_date 2018/05/17 · openalex updated_date 2026/08/05
We provide analytical and numerical results concerning multi-scale correlations between the resolved velocity field and the subgrid-scale (SGS) stress-tensor in large eddy simulations (LES). Following previous studies for Navier–Stokes equations, we derive the exact hierarchy of LES equations governing the spatio-temporal evolution of velocity structure functions of any order. The aim is to assess the influence of the subgrid model on the inertial range intermittency. We provide a series of predictions, within the multifractal theory, for the scaling of correlation involving the SGS stress and we compare them against numerical results from high-resolution Smagorinsky LES and from a-priori filtered data generated from direct numerical simulations (DNS). We find that LES data generally agree very well with filtered DNS results and with the multifractal prediction for all leading terms in the balance equations. Discrepancies are measured for some of the sub-leading terms involving cross-correlation between resolved velocity increments and the SGS tensor or the SGS energy transfer, suggesting that there must be room to improve the SGS modelisation to further extend the inertial range properties for any fixed LES resolution.