Molecular dynamics study of convective heat transfer in ordered rough nanochannels

Nanostructures can enhance the convective heat transfer process in nanochannels. The ordered rough nanochannels with different periodic sinusoidal structures are established using the molecular dynamics method to explore the internal mechanism of the effects of nanostructures on convective heat transfer. The potential energy distribution, the mass density distribution, the temperature distribution, and the velocity distribution are obtained to analyze the effects on heat transfer and fluid flow caused by different types of ordered rough surfaces. Moreover, the velocity slip length, the thermal length, and the Nusselt number are also calculated. The results show that with the increase in surface roughness, the thermal slip length decreases, and the Nusselt number increases, indicating that the heat transfer process is improved. However, the decrease of velocity slip length indicates that the fluid flow process becomes worse. The expansion of the low potential energy region and the high mass density region enhances the heat transfer process at the solid-liquid interface. The accumulation of more atoms at the solid-liquid interface hinders the development of the flow field and makes the flow process worse. This research provides an understanding of the convective heat transfer in ordered rough nanochannels, which can guide the design of electronic devices' cooling and fluid transport. (C) 2021 Elsevier B.V. All rights reserved.