uma revisão sobre a turbulencia

“main” — 2011/7/22 — 12:00 — page 21 — #1

Revista Brasileira de Geof´sica (2011) 29(1): 21-41 ı © 2011 Sociedade Brasileira de Geof´sica ı ISSN 0102-261X www.scielo.br/rbg ˜
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UMA REVISAO SOBRE A TURBULENCIA E SUA MODELAGEM e Jos´ Francisco Almeida de Souza1 , Leopoldo Rota de Oliveira2 , Jos´ Luiz Lima de Azevedo2 , e 3
Ivan Dias Soares e Mauricio Magalh˜es Mata4 a Recebido em 25 marco, 2010 / Aceito em 25 fevereiro, 2011
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Received on March 25, 2010 / Accepted on February 25, 2011

ABSTRACT. The movements are characterized by turbulent fluctuations in instantaneous speed, temperature and other scalars. As a consequence of these fluctuations, the turbulent state in fluid contributes significantly to transport momentum , heat and mass. Turbulence is defined as a state of the flow in which the time dependent variables exhibit irregular fluctuations which are seemingly random such that, in practice, only statistical properties can be recognized and subjected to analysis. The study of transport phenomena is greatly hampered by the presence of these fluctuations. Any simplification in the analysis of the effects of turbulence is extremely advantageous in physical, mathematical and numerical terms. The constant search for such simplifications is one of the main goals in the developing of new models of turbulence. This article aims to review the phenomenon of turbulence and its modeling, focusing on its theoretical foundations and on the main technical approaches used in the modeling of the phenomenon.
Keywords: turbulence, turbulence modeling, boundary layer, scales of turbulence.

RESUMO. Os movimentos turbulentos s˜o caracterizados por flutuacoes instantˆneas de velocidade, temperatura e outros escalares. Como consequˆncia destas a ¸˜ a e e flutuacoes, o estado turbulento em um fluido contribui significativamente no transporte de momentum , calor e massa. Define-se turbulˆncia como um estado de
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escoamento do fluido no qual as