Conjugate natural convection in a closed domain containing a heat-releasing element with a constant heat-release intensity

Mathematical modeling of gravitational heat convection in a closed rectangular domain with finite-thickness heat-conducting walls in the presence of a heat-releasing element with a constant heat-release intensity located at the base of the domain under conditions of convective-radiative heat transfer on one external boundary is performed. The influence of constitutive parameters (Grashof number and relative thermal conductivity) and flow unsteadiness on local thermohydrodynamic characteristics (streamlines and temperature field) and on the integral parameter (mean Nusselt number on the inner surface of the solid walls) is analyzed. Results obtained for two models of the heat source (with a constant temperature and with a constant heat-release intensity) are compared.