On the effect of prandtl number to subgrid-scale heat flux models
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Cita com:
hdl:2117/384538
Tipus de documentText en actes de congrés
Data publicació2022
EditorScipedia
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Abstract
Estimations of the grid size and computational cost for direct numerical simulation (DNS) and large-eddy simulation (LES) of Rayleigh-Bénard convection (RBC) are presented in the {Ra, P r} phase space. Computational requirements to reach the so-called asymptotic Kraichnan or ultimate regime of turbulence using DNS are far too expensive. Therefore, we turn to LES to predict the large-scale behavior at very high Ra-numbers. However, a priori alignment studies clearly show why the modelization of the SGS heat flux is the main difficulty that (still) precludes reliable LES of buoyancy-driven flows at (very) high Ra-numbers. This inherent difficulty can be by-passed by carrying out simulations at low-P r numbers where no SGS heat flux activity is expected. This opens the possibility to reach the ultimate regime carrying out LES of RBC at low-P r using meshes of 1010 -1011 grid points. Nevertheless, to do so, we firstly need to combine proper numerical techniques for LES (also DNS) with an efficient use of modern hybrid supercomputers.
CitacióTrias, F.X. [et al.]. On the effect of prandtl number to subgrid-scale heat flux models. A: European Congress on Computational Methods in Applied Sciences and Engineering. "Collection of papers presented at the 8th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS Congress 2022)". Scipedia, 2022, ISBN 9788412322286. DOI 10.23967/eccomas.2022.211.
ISBN9788412322286
Versió de l'editorhttps://www.scipedia.com/public/Trias_et_al_2022a
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ECCOMAS22_SGS_heat_flux_paper.pdf | 3,325Mb | Visualitza/Obre |