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

Author(s)

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

Affiliation

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

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

• Document type: Journal article
• Source: COMPUTERS & FLUIDS; v. 230, NOV 15 2021.
• Web of Science Citations: 0

Abstract

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)

• FAPESP's process: 19/14371-7 - Study on exchanges between earth's surface and atmosphere using Large-Eddy Simulation
• Grantee: Livia Souza Freire Grion
• Support Opportunities: Scholarships in Brazil - Young Researchers
• FAPESP's process: 13/07375-0 - CeMEAI - Center for Mathematical Sciences Applied to Industry
• Grantee: Francisco Louzada Neto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 18/24284-1 - Study on exchanges between Earth's surface and atmosphere using Large-Eddy Simulation
• Grantee: Livia Souza Freire Grion
• Support Opportunities: Research Grants - Young Investigators Grants