TURBULENCE IN WALL REGION MODELING / ASPECTOS DA MODELAGEM DA TURBULÊNCIA NA REGIÃO DA PAREDE
AUTOR(ES)
HUGO DARIO PASINATO
FONTE
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia
DATA DE PUBLICAÇÃO
30/01/1998
RESUMO
This thesis presents the results of research work aiming at low Reynolds turbulence modeling. For an stablished boundary layer turbulent low Reynolds flow in the viscous layer near a wall was characterized based on experimental data and empirical polynomials. On this basis an analysis of the distribuition of the mean values in the near-wall region was performed allowing for the proposal of a low Reynolds turbulence model within a two-equation model methodolgy. The low Reynolds proposal involves a closure to the dissipation equation and the proposal of an effective turbulence viscosity expression. The dissipation equation closure like as the effective viscosity proposal were made based on previous results of scale time rate analysis through the viscous region. On the other hand, the effective turbulence viscosity expression allows for the representation of the Reynolds stress as a function of mean flow kinetic energy. The low Reynolds turbulence modeling proposal can be seen as a complementation of two eqaution models for low Reynolds turbulence. The model was tested in several case tests of turbulent flow with different kind of mean shear, frequently used for turbulence model assessment. As main results of this work can be mentioned the systematic use of experimental data to build, analyze and test turbulence models; the closure of the dissipation equation without damping functions and the turbulence effective viscosity expression for the viscous region. This last proposed relation allows for the attainment of a mean velocity distribuition profile in the buffer region, which adequately fits experimental data.
ASSUNTO(S)
turbulence modelagem modelling turbulencia regiao da parede wall region
