Thermal Performance Analysis of Nanofluid Thermal Conductivity Models in a Cooling Chamber

Abstract

This study focused on the numerical modeling of mixed convection heat transfer in two-dimensional double lid-driven cavity filled with alumina–water nanofluid. Four different thermal conductivity models as well as experimental thermal conductivity data of Das et al. are used to estimate nanofluid thermal conductivity that incorporates the effects of nanoparticles concentration, Brownian motion, temperature, nanoparticle size, and interfacial-layer thickness. These models are used to evaluate the heat transfer enhancement and the increase of the average Nusselt number on a hot wall. The governing stream-vorticity equations are solved using a second-order central finite-difference scheme, coupled to the conservation of mass and energy. The main sensitive parameters of interest selected to investigate the thermal conductivity models are volume fraction of the nanoparticles (), Richardson number , and Reynolds number . The performance study of the thermal conductivity models and the interpretation of the corresponding results of isothermal lines, temperature profile, and average Nusselt number on a hot wall are done in a different range of , Richardson number, and Reynolds number for forced, mixed, and natural convections. As a result, it found that higher heat transfer is produced when the effects of nanoparticle size and interfacial-layer thickness are considered.