A Numerical Study of Natural Convection Heat Transfer in a Composed Thermal Diode; Natural convection; nclosure; heat transfer

摘要

The effects of inclination on the steady natural convection local heat transfer characteristics in an air-filled enclosure, which is composed of rectangular and parallelogrammic portions, are studied numerically. In this investigation, two geomet- rical aspect ratios are introduced: one for a parallelogrammic portion of an enclosure, the other for a rectangular one. The governing equations for a two-dimensional, laminar, natural convection process in an enclosure are discretized by the control volume approach which ensures the conservative characteristics to be satisfied in the calculation domain, and then solved by a modified SIMPLE algorithm. The momen- tum and energy equations are coupled through the buoyancy term. Computations are carried out for Prandtl number Pr = l and Rayleigh number Ra = 2.7 X l0~8. In order to obtain a greater understanding of the flow and heat transfer behaviors, flow pattems with streamlines and isotherms at different inclination angles are shown. Also, the effects of numbers of installed guide vanes in a composed enclosure are studied to consider the enhancement of heat transfer of the inner diode.