Numerical studies on laminar natural convective air flow in inclined channels

Steady laminar natural convective flow induced by a heat source in an inclined channel was investigated numerically. Navier-Stokes equations with Boussinesq approximations in three-dimensional forms were solved by the finite volume technique. Two channel configurations with the ends open and closed were considered. The inclination angle varied from 0° to 20° on increments of 5° for both channel configurations. Rayleigh numbers were estimated from the channel width. Effects of varying the Rayleigh number of values 10^sup 3^, 10^sup 4^, 10^sup 5^ and 10^sup 6^ on heat transfer were studied. Predicted streamlines and isothermals in the two channel configurations; and contours of longitudinal velocity components at open end walls are presented. It is observed that heat transfer through the hot wall is not sensitive to the inclination angle at a certain Rayleigh number. However, it increases with Rayleigh number at all inclination angles. Whether the end walls are open or not has little effect on the heat transfer through the hot wall under the same conditions. A reduced scale model channel with two open ends inclined at an angle of 20° to horizontal was constructed. Experiments on air flow field induced by a heat source were carried out in this scale model. Air temperature measured at the vertical central plane was applied to justify the numerical prediction.Department of Building Services Engineerin