Heat transfer mechanism for abnormal enhancement of thermal conductivity in a nanofluidic system by molecular dynamics

Molecular dynamics simulation was used to investigate effects of microscopic characteristics of interfacial layer of ZnO/W and Zn/W nanofluids to reveal abnormal enhancement of thermal conductivity. The thermal conductivities of ZnO/W nanofluids were higher than those of Zn/W nanofluids. It was found that fewer water molecules with slower velocities leave the interfacial layer and trajectory lines of water molecules are more concentrated to form a more stable interfacial layer in the ZnO/W nanofluidic system. A higher number of nanoparticle atoms and the probability of finding molecules evaluated by mean square displacement and radial distribution function, lead to the formation of a more stable interfacial layer. This study presents a new parameter S to evaluate the stability of the interfacial layer to determine the effect of its on the thermal conductivity and a new perspective to improve the heat transfer characteristics of nanofluids.