Abstract
A numerical study has been performed for combined natural convection and thermal radiation heat transfer in the air-filled enclosed space. Finite volume method and SIMPLE algorithm has been applied for computation. A radiative Nusselt number increases with increase of emissivity, in addition, a natural convection is enhanced by thermal radiation and convective Nusselt number also increases. When the temperature of the heating surface is high, convective Nusselt number and radiative Nusselt number are about the same order and the total Nusselt number becomes very large.
