Three-dimensional simulation of conjugate heat transfer using the hybrid lattice Boltzmann-finite difference method

Abstract

This paper presents a three-dimensional numerical study of natural convection and conduction thermal phenomena using MRT-lattice Boltzmann and finite difference approaches. Conduction is examined using a simple conjugate heat transfer technique, which is predicated on the assumption of continuity of heat flux and temperature at the solid/fluid interfaces, instead of utilizing the conventional method based on the solution of the conduction equation. Several parameters such as Rayleigh number and thermal conductivity related to common construction materials are also investigated to explore their effects on the evolution of heat transfer. The obtained results show that augmentation of the Rayleigh number increases the quality of heat transfer by around 35–293% for various values of thermal conductivity ratio (solid/fluid). While the increase in thermal conductivity ratio enhances the heat transfer rate by about 212–685%, where the maximum rate of heat exchange is still the same for the thermal conductivity ratio ≥1000. Entropy generation is also examined in this paper to evaluate the efficiency of our studied system. The performed investigations indicate that the rate of entropy generation due to heat transfer, friction, and total entropy generation varies significantly with increasing Rayleigh number and thermal conductivity of the solid.