Calculation of Flow in Transition Duct Using Second-Order Closure and WallFunctions

摘要

The results presented in this paper are part of an ongoing program of researchaimed at the development and verification of a generally-applicable portable parallel code for the prediction of turbulent flows which utilize advanced turbulence models. The focus here has been on the flow in a circular-to-rectangular transition duct which has well-documented experimental data for model validation. The Reynolds-stress model used here utilizes the complete pressure strain model of Speziale et al., which is free of any wall-distance parameters. It was found that the model can reproduce, farily satisfactorily, the principal features of the flow, including the distortions of the mean velocity and turbulent fields caused by the cross-sectional secondary-velocity field. However, the most important conclusion coming out of this short technical note is that, contrary to some previous studies, it is possible to capture all the main features of this type of flow with second-order closure when used in conjunction with wall functions.