Abstract
In this study, effects of aspect ratio on mixed convective heat transfer in horizontal rectangular duct were examined numerically and experimentally. The working fluid was water. As thermal boundary conditions, the upper and the bottom walls were insulated thermally and the side walls were heated and cooled walls respectively in the heat transfer section. In the numerical analysis, the fluid flow and the temperature distributions for Ri=1.61, Pr=6.99, Re=100, and aspect ratio Ar=0.2 10, were obtained by solving non-dimensional governing equations using SIMPLE procedure. The QUICK scheme was applied to convection term of these equations. In the experimental analysis, the flow behavior for Ar=0.5 2 was visualized by dye-injection method. Results show that the swirl flow was generated along the main flow direction. The vertical and horizontal velocities at the cross section were increased with A,. The prediction equations of the pitch length and the average Nusselt number were derived.
