Abstract
The aim of this research is to identify possible mechanisms that govern heat transport at a solid–liquid interface using molecular dynamics. The study reveals that, unlike its bulk analogue, a liquid in a nanochannel sustains long-lived collective vibrations, phonons, which propagate over longer timescales and distances. The larger phonon mean free path in nanochannels is attributed to the greater structural order of the liquid atoms and to the larger liquid relaxation time—the time in which the liquid structure remains unchanged and solid-like. For channels of height less than 10sigma, long-range phonons are the dominant means of heat transfer in the directions parallel to the channel walls. The present findings are in agreement with experiments, which have observed significantly increased liquid relaxation times for the same range of channel heights. Finally, it is argued that confinement introduces additional transverse modes of vibration that also contribute to the thermal conductivity enhancement.
Highlights
Despite the increasing use of micro- and nanoflows in many fields, the effect of confinement on the properties of liquids is only partly understood
For channel heights less than 10, we show that the thermal conductivity is dominated by long-range phonons
We have shown that the thermal conductivity in the direction parallel to the solid surfaces is enhanced almost
Summary
Despite the increasing use of micro- and nanoflows in many fields, the effect of confinement on the properties of liquids is only partly understood. The structural order of the liquid atoms has been found to increase to various extents depending on the liquid and solid properties (Bai et al 2010; Klein and Kumacheva 1995; Sun et al 2002; Koga et al 1997, 2000). The Kapitza resistance (thermal resistance at an interface), often a bottleneck of cooling devices, can be decreased by choosing lyophilic materials that are wettable by the cooling liquid (Barrat and Chiaruttini 2003; Kim et al 2008) This is a direct result of the increasing density of the structured liquid layers next to the channel walls (Xue et al 2004; Alexeev et al 2015)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
