Turbulence modeling in geophysical flows - Part I - first-order turbulent closure modeling

• Autor(a) principal: Souza, José Francisco Almeida de
• Data de Publicação: 2014
• Outros Autores: Azevedo, José Luiz Lima de, Oliveira, Leopoldo Rota de, Soares, Ivan Dias, Mata, Mauricio Magalhães
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da FURG (RI FURG)
• Texto Completo: http://repositorio.furg.br/handle/1/5857; http://dx.doi.org/10.1590/rbgf.v32i1.395
• topic: Turbulence modeling; Turbulence models; First-order models; First-order turbulent closure; Modelagem da turbulência; Modelos de turbulência; Modelos de primeira ordem; Fechamento turbulento de primeira orde

The usage of so-called turbulence closure models within hydrodynamic circulation models comes from the need to adequately describe vertical mixing processes. Even among the classical turbulence models; that is, those based on the Reynolds decomposition technique (Reynolds Averaged Navier-Stokes – RANS), there is a variety of approaches that can be followed for the modeling of turbulent flows (second moment) of momentum, heat, salinity, and other properties. Essentially, these approaches are divided into those which use the concept of turbulent viscosity/diffusivity in the modeling of the second moment, and those which do not use it. In this work we present and discuss the models that employ this concept, in which the viscosity can be considered constant or variable. In this latter scenario, besides those that use the concepts of mixture length, the models that use one or two differential transport equations for determining the viscosity are presented. The fact that two transport equations are used – one for the turbulent kinetic energy and the other for the turbulent length scale – make these latter ones the most complete turbulent closure models in this category.