Effect of silver nanoparticle volume fraction on thermal conductivity, specific heat and viscosity of ethylene glycol base silver nanofluid: A molecular dynamics investigation

Abstract

Using molecular dynamics (MD) simulation, the effect of temperature and Ag nanoparticles volume fraction in Ethylene Glycol (EG) base fluid is investigated in the context of some thermophysical properties like thermal conductivity (TC), viscosity, and specific heat. The 12–6 Lennard-Jones (LJ) potential is considered to model the Van der Walls interaction between the atoms of the nanofluid. The ability of nanoparticles to change the characteristics of a fluid is determined by its diffusive qualities relative to the fluid. TC of the base fluid increases with temperature. The enhancement of the relative TC to the base fluid TC (knf/kbf) is due to the reduction of the condensation of the fluid surrounding the nanoparticle. We also show that viscosity increases with volume fraction but reduces with temperature. Moreover, a nonlinear increment of TC and Viscosity with volume fraction is seen, which is consistent with the results of different models. Mean square displacement (MSD) calculation is performed to understand the mechanism of thermal conductivity enhancement. It is observed that viscosity decreases nonlinearly with increasing particle diameter from 1.1 nm to 1.5 nm. To gain a better understanding of the local structure and organization of the studied system total and partial radial distribution functions (RDFs) are investigated. The results provide important information regarding the properties of the nanofluid (EG + Ag) with respect to concentration, temperature etc. As EG is a more complex structure and lower freezing point than water, so we try to simulate this base fluid with a high TC nanoparticle (Ag), because, till now, maximum simulations are performed on Argon or water-based nanofluid.