Comparison of turbulence models for film flow analysis in a rib-roughened narrow duct

In order to improve the prediction accuracy of the film flow analysis in an extremely narrow duct with roughness, validity and adequacy of turbulence models on the film flow analysis was evaluated. Four kinds of turbulence models are considered: standard k-ε model; realizable k-ε model; Reynolds stress model; and large eddy simulation model. As for the predicted results by these turbulence models on the generation, scattering and disappearance of droplets a great difference was seen at each other result. The turbulence kinetic energy in a narrow duct for each turbulence model was also estimated. Furthermore, an effect of the turbulence model to the instability of the interface on the film flow was clarified quantitatively. (author)