Natural convection heat transfer in a cubical enclosure with two active sectors on one vertical wall

Natural convection in a cubical enclosure with active surfaces on the same wall is studied numerically over a wide range of Rayleigh number. Nusselt numbers exceed the ones for a side heated cavity at low Ra. The transition to a convective regime is delayed to a very high Ra. The flow patterns and temperature distribution are described and an expression for overall heat transfer is proposed.