Numerical Study of Natural Convection Energy Transfer in a Grooved Cavity Using the Hybrid Lattice Boltzmann Method

Abstract

In this work, natural convection in a grooved rectangular cavity with aspect ratio R =2 is analyzed using a hybrid numerical approach combining the lattice Boltzmann method and the finite-difference technique. The introduction of two grooves in the cavity geometry aims to improve heat transfer passively, using air as the fluid with a Prandtl number of 0.71. The results show a significant improvement in heat transfer efficiency, with a 76% gain in Nusselt number at a Rayleigh number (Ra) set at 10^3 and 43% at Ra=10^5, compared with the conventional Rayleigh-Bénard configuration. These improvements are attributed to modified flow structures and deformed isotherms near the grooves, favoring complex fluid dynamics and improved heat exchange. These results suggest that grooved geometries can be used effectively to enhance heat transfer in natural convection, making them suitable for a variety of industrial applications.