Numerical analysis of turbulent flow and heat transfer in a square sectioned U-bend duct by elliptic-blending second moment closure
A second moment turbulence closure using the elliptic-blending equation is introduced to analyze the turbulence and heat transfer in a square sectioned U-bend duct flow. The turbulent heat flux model based on the elliptic concept satisfies the near-wall balance between viscous diffusion, viscous dissipation and temperature-pressure gradient correlation, and also has the characteristics of approaching its respective conventional high Reynolds number model far away from the wall. Also, the traditional GGDH heat flux model is compared with the present elliptic concept-based heat flux model. The turbulent heat flux models are closely linked to the ellipticblending second moment closure which is used for the prediction of Reynolds stresses. The predicted results show their reasonable agreement with experimental data for a square sectioned U-bend duct flow field adopted in the present study.
Key WordsSecond Moment Closure Square Sectioned U-bend Duct Flow Secondary Flow Elliptic-Blending Model Turbulent Heat Transfer
Unable to display preview. Download preview PDF.
- Chang, S. M., Humphrey, J.A. C. and Modavi, A., 1983, “Turbulent Flow in a Strongly Curved U-Bend and Downstream Tangent of Square Cross-Sections,”Phys. Chem. Hydrodyn., Vol. 4, pp. 243–269.Google Scholar
- Choi, Y. D., Iacovides, H. and Launder, B. E., 1989, “Numerical Computation of Turbulent Flow in a Square-Sectioned 180 Deg. Bend,”ASME J. of Fluid Engng, Vol. III, pp. 59–68.Google Scholar
- Daly, B. J. and Harlow, F. H., 1970, “Transport Equation in Turbulence,”Phys. Fluids, pp. 2634–2649.Google Scholar
- Johnson, R. W., 1984, “Turbulent Convecting Flow in a Square Duct with a 180° Bend; Experimental and Numerical study,” PhD. Thesis, UMIST.Google Scholar
- Shin, J. K., An, J. S. and Choi, Y. D., 2005, “Prediction of Combined Forced and Natural Turbulent Convection in a Vertical Plane Channel with an Elliptic-Blending Second Moment Closure,”Trans. of the KSME (B), Vol. 29, pp. 1265–1276.Google Scholar
- Suga, K. and Abe, K., 2000, “Nonlinear Eddy Viscosity Modelling for Turbulence and Heat Transfer Near Wall and Shear-Free Boundaries,”Int. J. Heat Mass Transfer, Vol. 21, pp. 37–48.Google Scholar