Performance examination of realizable k-epsilon turbulence model in periodically fully developed turbulent flow and heat transfer

In this study, turbulent flow and heat transfer behaviour have been investigated by using two different turbulence models in a channel whose cross-sectional area is varying periodically. ANSYS Fluent 12.1 CFD program has been used and Realizable and Standard k-epsilon results were presented with each other and experimental data comparatively. The periodic fully developed flow condition was obtained with periodically defined on the bottom wall mounted ribs. Governing equations were solved for one period under the stream wise periodic, constant heat flux at the bottom wall, adiabatic at the ribs and at the top wall boundary conditions. It is seen that the results from the turbulence models are generally in good agreement with experimental data given in the literature. On the other hand, there are some inconsistencies between comparing results. It can be explained that these inconsistencies occur generally in weak region in which backward flows exists behind the rib. Eventually, it is concluded that Realizable k-epsilon model predicts well-reattachment point location and states more realistic results than Standard k- epsilon model in weak region.