Unsteady conjugate thermogravitational convection in a cylindrical region with local energy source

The mathematical modelling of unsteady regimes of natural convection in a closed cylindrical region with a heat-conducting shell of finite thickness was carried out in the presence of a local heat source under the conditions of convective heat exchange with the ambient medium. The mathematical model was constructed in dimensionless variables "stream function - vorticity vector - temperature" in the cylindrical coordinate system. The influence of the Rayleigh number, 10(4) <= Ra <= 10(6), of the unsteadiness factor 0 < tau < 300, of the thermal conductivity ratio lambda(2,1) = 5.7.10(-4), 4.3.10(-2), and the energy source sizes on both local characteristics (streamlines and temperature fields) and on the integral complex (the mean Nusselt number on typical boundaries) was analysed in detail. Thermohydrodynamic peculiarities due to the geometry of the object of research were established.