Laminar natural convection from an isoflux discrete heater in a vertical cavity

Laminar natural convection heat transfer in an air filled vertical square cavity differentially heated with a single isoflux discrete heater on one wall with top and bottom adiabatic surfaces is numericafly studied. The coupled unsteady two-dimensional conservation equations are solved by employing a forward time central space implicit finite difference scheme. Numerical results reveal that the local Nusselt number decreases along the length of the heater at constant value of the modified Rayleigh number (Ra*) with slight enhancement near the trailing edge. The heater location for the maximum heat dissipation rate is Rayleigh number dependent, which is in agreement with previous experimental and numerical results. A correlation for this location is obtained in addition to a relation for the dependence of the average Nusselt number on the modified Rayleigh number and the location parameter (s/L). Average Nusselt number variation for s/L = 0.25 to 0.75 and Ra* =10(3) to 10(6) is presented and compared to the available correlations for full contact and discretely heated enclosures.