Natural convection in enclosures with localized heating from below and symmetrical cooling from sides

Natural convection of air in a two-dimensional, rectangular enclosure with localized heating from below and symmetrical cooling from the sides has bee n numerically investigated. Localized heating is simulated by a centrally l ocated heat source on the bottom wall, and four different values of the dim ensionless heat source length, 1/5, 2/5, 3/5 and 4/5 are considered. Soluti ons are obtained for Rayleigh number values from 10(3) to 10(6). Local resu lts are presented in the form of streamline and isotherm plots as well as t he variation of local Nusselt number on the heated wall. Finally, the avera ge Nusselt number at the heated part of the lower wall, was shown to increa se with an increase the Rayleigh number. Ra, or of the,nondimensional heat source thickness, epsilon.