This work completes experimental and calculated study in free convection of water on both sides of a wall. The specified process is studied for the location of the inner container filled with the electrically heated water, inside the outer container filled with cold water heated through walls of the inner container. The heat transfer in the conditions of bilateral free convection in that process is not reduced to standard cases. Indeed, both the temperature condition of walls of the inner container, and heat flux through walls are characterized by extreme unevenness. Respectively, it examines the average characteristics of the heat transfer from a hot water to cold, based on the average water temperatures in inner and outer containers. The generalized correlation is obtained. Calculations were carried out for all three structures and some their constructive variations, as well as for a large number of operating conditions. The correlation results were obtained for slow transition processes of heating, and for the steady-state regimes. Walls of the outer container were either adiabatic, or convective to the environment. Also constant wall temperatures for part of the calculated steady-state regimes, including asymmetrical boundary conditions were analyzed. Calculations and experimental study were carried out for the range of Ra* = 1011 - 4•1013. The good agreement of calculated and experimental results of both the primary data, and presentation in the form of a correlation (1), testifies to the correctness applied in calculation of the laminar model of CFD FLUENT 6.3.
