Free Convection Heat Transfer of Nanofluids into Cubical Enclosures with a Bottom Heat Source: Lattice Boltzmann Application

The main purpose of this work is to investigate the hydrodynamic and thermal characteristics of an Ag-water nanofluid within a cubical enclosure, including a heat source which located at the center of the bottom wall. Due to its crucial role in the characterization of the main transfer into such configurations, the impact of some parameters is widely inspected. It consists the Rayleigh number (10³ to 10⁶), the nanoparticles volume fraction (0% to 10%), the width (10% ≤ w ≤ 40%) and the height of the heat source (10% ≤ h ≤ 50%). To do so, a numerical code based on the Lattice-Boltzmann method, coupled with a finite difference one, is utilised. The latter has been validated after comparison between the present results and those of the literature. It is to note, at the end, that the three dimensions D3Q19 model is adopted based on a cubic Lattice, where each pattern of the latter is characterized by nineteen discrete speeds.