Buoyant convection of a variable-viscosity fluid in an enclosure with discrete protruding heaters

A study is made of buoyant convection in a rectangular enclosure, with protruding heaters attached on one vertical wall. The total amount of heat generated in the entire heaters is fixed. Numerical solutions to the Navier-Stokes equations are secured for the Rayleigh number ranging 104–108. In order to deal with more practical situations, a fluid of temperature-dependent viscosity is considered. Detailed descriptions are presented for the flow and temperature fields. Physical interpretations are provided for the heat transfer mechanism. At low Rayleigh number, heat transfer across the enclosure is invigorated as the number of heaters increases. At high Rayleigh number, there exist an optimum number of heaters that yields maximal system-wide heat removal in the enclosure.