Nonequilibrium molecular dynamics simulation of coupling between nanoparticles and base-fluid in a nanofluid

► Nonequilibrium heat transfer in a copper-argon nanofluid is investigated by molecular dynamics simulation. ► The coupling factor is proportion to the volume fraction of the nanoparticle and inverse proportion to nanoparticle diameter. ► In the temperature range of 90-200 K, there is no temperature effect on the coupling factor. ► The nanoparticle aggregation results in a decrease of the coupling factor.