Numerical modeling of conjugate thermogravitational convection in a closed system with a radiant energy source in conditions of convective-radiative heat exchange at the external boundary

Mathematical modeling of conjugate natural convection in a closed rectangular cavity with a radiant energy source in conditions of convective-radiative heat exchange at the external boundary was conducted. The radiant energy distribution was set by the Lambert's law. Conduction and convection processes analysis showed that the air masses flow pattern is modified slightly over the time. The temperature increases in the gas cavity, despite the heat removal from the one of the external boundary. According to the results of the integral heat transfer analysis were established that the average Nusselt number (Nu_av) increasing occurs up to τ = 200 (dimensionless time). Further Nu_av has changed insignificantly due to the temperature field equalization near the interfaces "gas - wall".