The Impact of Roughness and Partitions In Thermal Convection to Enhance the Heat Transport

Abstract

Abstract This investigation delves into the profound influence of adiabatic partitions on heat transport within a square Rayleigh-Benard (RB) convection enclosure characterized by surface roughness on the lower hot and upper cold plates. These surface irregularities manifest as a rectangular base and a triangular apex. Employing two-dimensional (2D) direct numerical simulations across a Rayleigh number (Ra) range of 106 to 108 and a Prandtl number (Pr) of 1, our study focuses on strategically positioned adiabatic partitions between successive roughness elements. Notably, we uncover a significant enhancement in heat transport with the introduction of partition boards between consecutive roughness elements. As the number of partitions increases from one to four, the heat flux experiences a remarkable augmentation, reaching 2.3 times that of the classical square RB configuration. This enhancement arises from the breakdown of large-scale rolls into multiple rolls, a phenomenon intensified by increased partition height. Intriguingly, configurations featuring roughness with partitions exhibit a 2.7-fold increase in heat flux compared to the classical square RB setup. The interplay of surface roughness and partitions contributes to this improvement, with optimized gap distances between the conduction plate and partition heightening local velocity, thinning the thermal boundary layer, and augmenting overall heat flux. This study sheds light on the synergistic effects of adiabatic partitions and surface roughness in RB convection, indicating the potential for tailored design strategies involving partitions and surface modifications to optimize thermal performance across various applications.