Large Eddy Simulations of convergent-divergent channel flows at moderate Reynolds numbers

Autor(es)

Schiavo, Luiz A. C. A. ^[1] ; Jesus, Antonio B. ^[2] ; Azevedo, Joao L. F. ^[3] ; Wolf, William R. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, BR-13083970 Campinas, SP - Brazil

^[2] Inst Tecnol Aeronaut, BR-12228900 Sao Jose Dos Campos, SP - Brazil

^[3] Inst Aeronaut & Espago, BR-12228903 Sao Jose Dos Campos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW; v. 56, p. 137-151, DEC 2015.
• Citações Web of Science: 3

Resumo

The paper is focused on the study of fully turbulent channel flows, using Large Eddy Simulations (LES), in order to address the effects of adverse pressure gradient regions. Analyses of the effects of streak instabilities, which have been shown to be relevant in such regions, are extended to moderate Reynolds numbers. The work considers two different channel geometries in order to further separate influences from wall curvature, flow separation and adverse pressure gradients. Turbulent kinetic energy and Reynolds stress budgets are investigated at separation and re-attachment points. The numerical approach used in the present work is based on the incompressible Navier-Stokes equations, which are solved by a pseudo-spectral methodology for structured grids. Wall-resolved LES calculations are performed using the WALE subgrid scale model. The study shows that the streak instability mechanism persists at higher Reynolds numbers with and without wall curvature in the adverse pressure gradient regions. Moreover, the observed effects are also present regardless of the existence of flow separation regions. Finally, the study of turbulent kinetic energy budgets indicates that, independently of the flow condition, there are well-defined patterns for such turbulent properties at separation and re-attachment points. (C) 2015 Elsevier Inc. All rights reserved. (AU)

• 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: 13/03413-4 - Investigação da geração e propagação de ruído em configurações aerodinâmicas utilizando aeroacústica computacional
• Beneficiário: William Roberto Wolf
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 14/07623-6 - Estudo numérico do efeito de uma perturbação geométrica em escoamentos turbulentos
• Beneficiário: Luiz Augusto Camargo Aranha Schiavo
• Modalidade de apoio: Bolsas no Brasil - Doutorado