Fast nanofluidics by travelling surface waves
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In this paper, we investigate the fast flow in nanochannels, which is induced by the travelling surface waves. The nanoscale fluid mechanism in nanochannels has been influenced by both amplitude and frequency of travelling surface waves, and the hydrodynamic characteristics have been obtained by molecular dynamics simulations. It has been found that the flow rate is an increasing function of the amplitude of travelling surface waves and can be up to a sevenfold increase. However, the flow rate is only enhanced in the limited range of frequency of travelling surface waves such as low frequencies, and a maximum fivefold increase in flow rate is pronounced. In addition, the fluid–wall interaction (surface wettability) plays an important role in the nanoscale transport phenomena, and the flow rate is significantly increased under a strong fluid–wall interaction (hydrophilicity) in the presence of travelling surface waves. Moreover, the friction coefficient on the wall of nanochannels is decreased obviously due to the large slip length, and the shear viscosity of fluid on the hydrophobic surface is increased by travelling surface waves. It can be concluded that the travelling surface wave has a potential function to facilitate the flow in nanochannels with respect to the decrease in surface friction on the walls. Our results allow to define better strategies for the fast nanofluidics by travelling surface waves.
KeywordsTravelling surface wave Nanofluidics Fast flow Molecular dynamics
The authors thank the reviewers for their constructive comments. JFX also thanks Professor Long Yu from Northwestern Polytechnical University for the useful discussions about the Rayleigh waves. The support of the National Natural Science Foundation of China (Grants No. 51506110 and 51676108) and Science Fund for Creative Research Groups (No. 51621062) was gratefully acknowledged.