NON LINEAR EDDY VISCOSITY MODELLING IN STEADY TURBULENT FLOWS DEVELOPED FROM LES ANALYSIS
Fernando Soares Alves1; Luiz Eduardo Bittencourt Sampaio1; Roney Leon Thompson1
1 Universidade Federal Fluminense
doi:10.20906/CPS/COB-2015-2587
Resumo
The Reynolds Average is applied to the balance equations of fluid motion in order to obtain governing equations for the mean variables. The result is a set of equations which need further closure once a new term arises from the averaging procedure, namely the so called Reynolds stress tensor. Although many different models can be found in the literature for non linear eddy viscosity models, mainly linear models are still applied, specially in engineering, for the closure of the problem . The present work aims in extending the base of tensors adopted to describe the deviatoric part of the Reynolds stress tensor in the linear model using tensor decomposition methods. We also approached the scaling of the coefficients for the models by using the kinetic turbulent energy and the norms of the tensors , instead of the usual procedure utilized in two equation models. The investigation is conducted by means of LES data and an scalar index is proposed in order to compare the different constructed models.
Palavras-chave: RANS; non Linear Eddy Viscosity Model; Reynolds Stress Tensor