Natural convection coupled to surface radiation in an air-filled square cavity containing two heat-generating bodies

The present numerical study focuses on the cooling by natural convection and surface radiation of two electronic components generating two different and uniform volumetric powers. These components are modeled by two square bodies placed inside a closed square cavity with a cold straight wall. Two configurations are analyzed based on the position of the two heat-generating bodies. In the first one (horizontal position configuration), the two bodies are located at the same height of the cavity, while they are placed at different heights in the second case (vertical position configuration). The effects of two Rayleigh numbers ($0\le ({\mathit{Ra}}_1,{\mathit{Ra}}_2)\le {10}^6$), the conductivity ratio ($0.01\le K\le 100$), and the emissivity ($0\le \epsilon \le 1$) on the heat transfer characteristics and the flow structure are analyzed. The data is displayed as streamlines, isotherms, velocity, and maximum temperature profiles, and local heat transfer on the active wall. The obtained results indicate that the choice of the appropriate configuration depends mainly on the deviation between the two Rayleigh numbers. Furthermore, the maximum temperature of a specific block decreases as the quantity of heat generated by the other block rises. We can also see that the maximum temperature of the two blocks decreases by about $50\%$ with the increase in the emissivity (from $0$ to $1$) or the conductivity ratio (from $0.1$ to $1$).