[01] A. Balabel, Mechanical Engineering Department, Faculty of Engineering, Taif University, Taif, Saudi Arabia; Mechanical Power Engineering Department, Faculty of Engineering, Menoufiya University, Shebin El-Kom, Egypt. [02] W. A. El-Askary, Mechanical Power Engineering Department, Faculty of Engineering, Menoufiya University, Shebin El-Kom, Egypt.

Recently, various turbulence models are widely developed in order to present a good prediction of turbulent characteristics in a wide range of industrial and engineering applications. Since the linear eddy-viscosity models show a poor prediction for some modern applications and their assumptions become invalid for separated flows, the non-linear eddy viscosity models become an important topic in the recent modeling of turbulent separated flow. The non-linear eddy viscosity models are expected to give a better prediction of reattaching turbulent flow as a result of the non-linear constitutive stress-strain relationship proposed to extend the applicability of the linear-eddy viscosity models. In the present paper, different linear and non-linear turbulence models are applied to predict one of the most complex geometry turbulent flows; namely, turbulent flow in asymmetric divergent channel. The abilities of these models to predict the turbulent flow characteristics in such complex geometry are examined and investigated numerically by solving Reynolds-averaged Navier-Stokes equations using the finite volume approach. The computed results are compared with the available experimental data in literature. The comparison of the obtained results with the experimental data has showed that the non-linear models have a better prediction, for the separated region and the associated turbulent characteristics, than the linear models. Consequently, the non-linear turbulence models could be considered as a powerful and a reliable tool in predicting such complex turbulent flows.

Asymmetric Sudden Expansion, Non-Linear Turbulence Models, Numerical Simulation, Separated Turbulent Flow

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