Systematic investigation of nanofluids: impact of nanoparticle charge and temperature on thermophysical properties

Abstract

This study systematically investigates the effects of nanoparticle (NP) charge and temperature on the thermophysical properties of nanofluids using molecular dynamics simulations. The interaction between charged nanoparticles and solvent particles significantly influences both viscosity and thermal conductivity. The nanoparticles are modeled with varying charges, and their impact on fluid behavior is analyzed in terms of radial distribution functions, viscosity, and thermal conductivity, computed using the Green-Kubo formalism. The findings reveal that increased NP charge leads to reduced aggregation, enhancing dispersion and lowering viscosity, while thermal conductivity exhibits complex behavior, decreasing with NP charge at moderate temperatures but increasing in the supercritical region. Temperature also plays a critical role, with nanofluids demonstrating typical shear-thinning behavior and a distinct phase-dependent response in thermal conductivity. These results provide valuable insights into optimizing nanofluid properties for applications such as coolant systems and lubricants, where both efficient heat transfer and low energy dissipation are crucial. The systematic analysis of charge and temperature effects contributes to a better understanding of the underlying mechanisms governing nanofluid behavior.