Abstract
A non-linear κ-ε model, which includes effects of the strain parameter and the rotation parameter, is applied to 2-D computation of the turbulent flow field behind a backward-facing step. Model coefficients are carefully adjusted in turbulence modelling. Coefficients in non-linear terms are firstly tuned focusing on the anisotropy in a simple shear flow. For the tuning of Cμ realizability conditions are examined in three types of 2-D basic flow patterns, namely, the simple shear flow, the flow around a saddle point and the flow around a focal point. Then, Cμ is adjusted as a function of the strain and rotation parameters considering the restrictions of realizability. Numerical simulatio are performed under the conditions of the laboratory test by Larousse et, al. Model performance is discussed through the comparison of the numerical and experimental results. The numerical result shows that the present model can qualitatively reproduce the cousplex2-D flow with separation and reattachment.To evaluate the accuracy of the computer code, comparisons with observed data were made and fairly good agreements were found between them.
