Rayleigh-Bénard thermal convection heat transfer characteristics with internal spherical arrays

In this paper, the effect of internal sphere on heat transfer characteristics of Rayleigh-Bénard (RB) thermal convection system is investigated experimentally. The effect of \phi porosity on heat transfer of RB system was studied by changing the diameter and distribution of the plexiglass sphere. Rayleigh number (Ra) changed from 5×10⁷ to 2×10⁹, and Prandtl number (Pr) was fixed at 5.5. The results show that under low Ra numbers, the filled spheres have almost no effect on the heat transfer of the RB system; under high Ra numbers, the heat transfer of the RB system is enhanced, with a maximum increase of 16%.