Large-Eddy Simulation of smooth and rough channel flows using a one-dimensional stochastic wall model

Autor(es)

Freire, Livia S. ^[1] ; Chamecki, Marcelo ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sao Carlos, SP - Brazil

^[2] Univ Calif Los Angeles, Los Angeles, CA - USA

• Tipo de documento: Artigo Científico
• Fonte: COMPUTERS & FLUIDS; v. 230, NOV 15 2021.
• Citações Web of Science: 0

Resumo

In this study a stochastic wall model based on the `'large-eddy'' version of the One-Dimensional Turbulence (ODT) model was developed for Large-Eddy Simulation (LES) of smooth and rough channel flows, with the primary goal of providing a refined turbulent flow field near the wall. This LES-ODT coupling was tested with the dynamic Smagorinsky and the scale-dependent Lagrangian dynamic subgrid-scale models. When compared to the same LES with a wall model based on a local law-of-the-wall, LES-ODT improved the one-dimensional energy spectra for all three velocity components close to the wall for both subgrid-scale models tested. More importantly, improving the LES wall model had a more positive effect in the near-wall spectra than improving the subgrid-scale model from the traditional dynamic to the scale-dependent Lagrangian dynamic model. For smooth channels, LES-ODT results compared well with DNS of Re-lambda = 590 and 5200; however, the variance modeled by the ODT presents discrepancies for all three velocity components, an issue inherent to ODT. Finally, the simulation of a channel flow with additional roughness modeled by a drag force was compared to data of atmospheric flow through a maize field, providing evidence of the potential for this approach to directly simulate complex near-wall phenomena. Given its high computational cost, the main use of the LES-ODT coupling is in studies that require a refinement of the near-wall region without the need to refine the entire LES domain. (AU)

• Processo FAPESP: 19/14371-7 - Estudo sobre as trocas entre a superfície do planeta e a atmosfera utilizando Large-Eddy Simulation
• Beneficiário: Livia Souza Freire Grion
• Modalidade de apoio: Bolsas no Brasil - Jovens Pesquisadores
• Processo FAPESP: 13/07375-0 - CeMEAI - Centro de Ciências Matemáticas Aplicadas à Indústria
• Beneficiário: Francisco Louzada Neto
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 18/24284-1 - Estudo sobre as trocas entre a superfície do planeta e a atmosfera utilizando Large-Eddy Simulation
• Beneficiário: Livia Souza Freire Grion
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores