Influence of nanoparticle properties on the thermal conductivity of nanofluids by molecular dynamics simulation

Abstract

The properties of nanoparticles (including shape, size, material, and volume concentration) may significantly influence the thermal properties of nanofluids. Through molecular dynamics simulations, the aim of this study is to investigate the influence of nanoparticle properties on the thermal conductivity of nanofluids and find an effective criterion for predicting thermal conductivity enhancement. By establishing a series of simulation models, thermal conductivities of nanofluids were calculated on the basis of the Green-Kubo formula. It was found that all the nanoparticle properties that have been considered in this work influence the thermal conductivity of nanofluids, and the influence rules were discussed. Furthermore, there is a positive correlation between the distribution of atomic potential energy and the thermal conductivity of nanofluids. Therefore, the ratio of energetic atoms in nanoparticles is proposed to be the criterion for predicting enhancement of the apparent thermal conductivity of nanofluids.

The behavior of the thermal conductivity near the melting temperature of copper nanoparticle

“…These features lead to potential application in many industrial sectors, particularly nanofluids which are used in cooling fluids for electronic systems, heating, cooling exchanger including transportation and energy production. Therefore, nanofluids containing suspended nanoparticle of copper showed large enhancement of thermal conductivity relative to those of pure fluids such as (Cu-Ar) nanofluid [13,14]. Extensive literature has been conducted in the past decade to investigate and predict various proprieties, heat transfer performance and the effective thermal conductivity of nanofluid consisting of several nanoparticles [15][16][17][18][19][20][21].…”

Molecular dynamics study of the thermal conductivity in nanofluids

“…Ghosh et al calculated the thermal conductivity of watercopper nanofluids using a hybrid MD-stochastic model, 5 they also observed a linear increase with the volume fraction. Additionally, Mohebbi et al 6 and Cui et al 7 also reported an increase in thermal conductivity of nanofluids with the volume fraction of nanoparticles. On the other hand, some studies observed that the rate of enhancement decreases with the volume fractions of nanoparticles, leading in some cases to a plateau at a relatively small volume fractions of 2% to 5%.…”

“…Cui et al suggested that the shape of the nanoparticles has an impact on the radial distribution function leading in turn to changes on the thermophysical properties of the nanofluid. 12 Nanoparticle clustering is one of the mechanisms proposed for the enhancement of thermal conductivity. 14 Kang et al.…”

Particle-shape-, temperature-, and concentration-dependent thermal conductivity and viscosity of nanofluids

“…It is defined as the maximum length to the minimum length in each particle. The ratio of the surface area to the volume of a particle is also considered as a shape parameter and its correlation to the thermal conductivity is investigated for silver nanofluid [58]. Since the surface area of the nanoparticle is in contact with the base fluid and conduction occurs by microscopic collisions of particles and movement of electrons within a body, we speculate that both the surface area and volume of the nanoparticle may play a vital role in the augmentation of the thermal conductivity.…”