Journal of the Faculty of Engineering and Architecture of Gazi University, cilt.15, ss.71-86, 2000 (SCI-Expanded)
In this study heat transfer, velocity and temperature distributions in a horizontal duct with rectangular cross section and an aspect ratio of 10 have been investigated under laminar mixed convection conditions using amethod of Computational Fluid Dynamics (CFD). The lower surface of the duct is subjected to a uniform heat flux, sidewalls are insulated, and the upper surface is exposed to the surrounding fluid. Governing equations were solved numerically and obtained solutions are compared with previously made experimental measurements. From an energy balance and by making use of temperatures obtained from the CFD analysis, local Nusselt numbers were calculated. Local Nusselt number results were compared with experimental results, and it was found that they are in good agreement. Results related to the buoyancy affected secondary flow and the onset of instability in duct flows were examined in detail. In addition, temperature contours as well as velocity vector distributions inside the duct are also presented in detail.