Natural convection-radiation cooling of a vertical divided vented channel

• Published in: Engineering computations 2006-01, Vol.23 (7), p.818-839
• Main Authors: Mezrhab, A., Bouali, H., Amaoui, H., Abid, C.
• Format: Article
• Language: English
• Subjects: Algorithms; Analytical and numerical techniques; Boundary conditions; Computational techniques; Convection and heat transfer; Cooling; Engineering; Exact sciences and technology; Experiments; Flows in ducts, channels, nozzles, and conduits; Fluid dynamics; Fundamental areas of phenomenology (including applications); Heat conductivity; Heat transfer; Mathematical methods in physics; Mathematical models; Monte Carlo simulation; Numerical analysis; Physics; Radiation; Rayleigh number; Studies; Temperature; Thermal energy; Turbulent flows, convection, and heat transfer
• ISSN: 0264-4401; 1758-7077
• DOI: 10.1108/02644400610689910

Purpose - The purpose of this paper is to study the radiation-natural convection interactions in a vertical divided vented channel. The effects of the surface emissivity, the vent opening position and size on the heat transfer and the flow structures inside the channel were studied.Design methodology approach - The governing differential equations are solved by a finite volume method, with adopting the SIMPLER algorithm for pressure-velocity coupling. The view factors were determined by using a boundary elements approximation and a Monte Carlo method.Findings - The effect of the radiation exchange is very important, it increases the average hot wall Nusselt number by more than 100 per cent. The contribution of the channel wall emissivity in the heat transfer is more important than that of the plate emissivity. The average hot wall Nusselt number increases with increasing the vent opening size, only in presence of the radiation exchange, and this increase is more pronounced, particularly when the vent opening is located near the channel inlet.Research limitations implications - The flow is assumed to be incompressible, laminar and two dimensional. The radiative surfaces are assumed diffuse-grey. The working fluid, air, is considered as transparent with respect to the radiation.Practical implications - The industrial applications of this study are solar collectors, thermal building, electronic cooling, aeronautics, chemical apparatus, nuclear engineering, etc.Originality value - In comparison to the preceding studies, the originality of this paper is the taking into account of the radiation exchange in a vented and divided channel.