Abstract:

In this study, steady-state hydrodynamically fully developed thermally developing three-dimensional laminar forced convection flow and heat transfer in a horizontal smooth trapezoidal duct were numerically investigated under uniform surface temperature condition. Numerical study was carried out for a Reynolds number range of 100 to 1000. Air (P r ∼= 0.7) was used as the heat transfer medium. A commercial CFD program Fluent 12.1 was used to carry out the numerical study. Average Nusselt numbers and average Darcy friction factors were presented for different Reynolds numbers. Local Nusselt numbers were plotted as a function of the distance along the duct. Velocity and temperature contours were given as graphically at different positions along the duct. The results obtained from this study were compared with the results of similar studies available in the literature, and the results were found to be in good agreement. It is seen that increase in Reynolds number causes decrease in friction factor and increase in heat transfer. Value of the Nusselt number for hydrodynamically and thermally fully developed laminar flow conditions in trapezoidal cross-sectioned duct was determined to be 2.95. Based on the present numerical investigation, new engineering correlations were obtained for the heat transfer and friction coefficient.

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