NUMERICAL PREDICTIONS OF MIXED CONVECTION AND FLOW SEPARATION IN A VERTICAL DUCT WITH ARBITRARY CROSS SECTION

Abstract

Recent studies on an efficient numerical approach for predicting mixed convection heat transfer and buoyancy-induced flow separations in the vertical rectangular ducts have been extended for the duct with complex geometry, testing it in several case studies. In this work, the three-dimensional parabolic model is modified by incorporating the curvilinear-coordinate finite volume method with the parabolic model. The validity of the approach has been demonstrated for several test cases, and the relative performance of the approach is also evaluated by comparing the numerical predictions with the full elliptic model solutions. The approach has been used to seek, in one case, detailed information on heat transfer and reversed flow behavior for the flow within a vertical parabolic duct. Results indicate that the three-dimensional parabolic model can be implemented and applied to predict mixed convective flows in ducts with arbitrary cross-sectional shapes, leading to satisfactory accuracy.