Investigation of the aggregation morphology of nanoparticle on the thermal conductivity of nanofluid by molecular dynamics simulations

•EMD simulations are carried out to calculate the thermal conductivities and fractal dimensions.•The thermal conductivity increases linearly with decrease of fractal dimension of aggregations.•The liquid atoms in nanolayer are “dynamically balanced”.•The explanation based on Kapitza resistance for heat transfer enhancement by nanolayer is queried.