Numerical Analysis of Turbulent Convective Heat Transfer Processes in a Square-Sectioned U-bend Duct

The flow and thermal field in a square-sectioned 180o U-bend were investigated using five turbulence models, namely Suga's quadratic and cubic low-Re k-ε, V2F k-ε, RSM-EVH and RSM-GGDH. All models managed to mimic the general flow and thermal patterns. The V2F-version used in this study, however, over-predicted the pressure-induced secondary flow and seems to need modifications and/or re-tuning of the coefficients to reduce its redistribution of turbulence energy. Suga's two k-ε variants are less CPU-demanding and perform relatively well and, hence are interesting candidates for industrial applications. The RSM models performed best