A molecular dynamics simulation of nanoscale convective heat transfer with the effect of axial heat conduction. (17th June 2016)

• Record Type: Journal Article
• Authors: Gu, You-Wei; Ge, Song; Chen, Min
• Is Part Of: Molecular physics. Volume 114:Number 12(2016)
• Page Start: 1922
• Page End: 1930
• Publication Date: 2016-06-17
• Subjects: Axial heat conduction -- convective heat transfer -- molecular dynamics simulation -- nanochannel; Molecules -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Molécules -- Périodiques; Chimie physique et théorique -- Périodiques; 539.6.05
• DOI: 10.1080/00268976.2016.1168884
• Languages: English
• ISSNs: 0026-8976

Abstract

ABSTRACT: Effective heat dissipation from nano-fluidic devices is sometimes necessary to ensure their performance and lifespan. In the molecular dynamics simulation of nanoscale convective heat transfer, thermostats cannot be directly applied to the fluid because of the non-uniform temperature distribution. Periodic boundary is typically utilised, but unrealistic axial heat conduction exists when there is a temperature difference between the outlet and images of inlet atoms. In this paper, the effect of axial conduction caused by periodic boundary is investigated through the Péclet number (Pe). Taking viscous dissipation into consideration, the magnitude of outlet thermal diffusion is observed to decrease with increasing Pe. The local average temperature of fluid changes in an exponential form except in the region close to the outlet. Results show that the contribution of outlet axial conduction to the local average temperature is less than 2.0% when Pe > 10. The main reason is that the magnitude of fluid velocity and viscous heat dissipation in nanochannels is much larger than that in macro-channels at the same Péclet number. Abstract :