Natural Convection in an Enclosure with a Pair of Discrete Heat Sources

An experimental and numerical study is carried out to investigate natural convection cooling characteristics of discrete heat sources in a rectangular enclosure. One of the sidewalls of the enclosure is heated by a pair of identical discrete heat sources, whereas the other sidewall is maintained at a constant temperature. The effect of the heat dissipation ratio of the heat sources on buoyancy-induced flow and heat transfer characteristics is investigated. Experimental studies are performed for a constant value of the modified Rayleigh number (Ra* = 7.7 x 10(5)) and three different values of the heat dissipation ratio (r(h) = q(1)/q(2) = 0 5, 1 and 2), whereas numerical studies cover the range of 10(4) to 5 x 10(6) for the modified Rayleigh number and different values of the heat dissipation ratios between 0.25 and 2. In the experimental study, qualitative flow visualization studies are carried out as well as temperature measurements. In the numerical study, a commercial computational fluid dynamics code in ANSYS Fluent is used. The variations of the surface temperatures, the hot spot temperature, and the mean Nusselt number with the modified Rayleigh number and the heat dissipation ratio are obtained. Results are presented in terms of streamlines, isotherms, and heat lines.