Investigation on the aggregation structure of nanoparticle on the thermal conductivity of nanofluids by molecular dynamic simulations

Abstract In this paper, equilibrium molecular dynamic simulations were used to calculate the thermal conductivity of Cu-Ar nanofluid with various initial aggregation structures at different volume fractions. The microscopic mechanism of the effect of nanoparticle agglomerate aggregation mode on the thermal conductivity of nanofluids was analyzed. Results showed that the particle size is the key factor to determine the aggregation structure of nanoparticles. The enhancement efficiency of diffusion-limited aggregation on the thermal conductivity of nanofluids was found to be greater than that of reaction-limited aggregation, and the effect of different aggregation structures on the diffusion coefficient of nanofluidic systems may be one of the potential mechanisms affecting the thermal conductivity of nanofluids.