Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Coherent structures in the atmospheric boundary layer using resolvent analysis
Submission Author:
Matheus Tozo de Araujo , PR
Co-Authors:
Matheus Tozo de Araujo, Livia S. Freire, Leandro Franco de Souza, André Cavalieri
Presenter: Matheus Tozo de Araujo
doi://10.26678/ABCM.COBEM2023.COB2023-0357
Abstract
In turbulent flows, large-scale coherent structures play a significant role in the flow dynamics, impacting the production of turbulence and containing the majority of the turbulence kinetic energy. Their identification and characterization, however, require detailed field measurements or refined numerical simulations, which comes at a high cost in particular for highly turbulent and variable flows such as the atmospheric boundary-layer (ABL). In this study, we investigate the ability of the Resolvent Analysis as low-cost tool to model ABL coherent structures, by providing only the mean flow field of the ABL. Resolvent analysis is a theoretical approach that takes the singular value decomposition of the linearized Navier-Stokes operator, treating the nonlinear terms as external forcing. The decomposition provides response modes that can be directly related to the most energetic coherent structures of the flow. Results are compared to the modes obtained from spectral proper orthogonal decomposition (SPOD) applied to detailed numerical data from Large-Eddy Simulations of the ABL. Cases in which the resolvent analysis provides the best agreement with SPOD are discussed. These results indicate that resolvent analysis can be used as a low-cost tool in the characterization of ABL coherent structures under different atmospheric and surface conditions, which has important practical implications in the modeling of atmospheric dynamics.
Keywords
turbulent flows, atmospheric boundary layer, Large Eddy Simulation, Resolvent Analysis, Spectral proper orthogonal decomposition
