Unsteady nanoscale thermal transport across a solid-fluid interface

Abstract

We simulate unsteady nanoscale thermal transport at a solid-fluid interface by placing cooler liquid-vapor Ar mixtures adjacent to warmer Fe walls. The equilibration of the system towards a uniform overall temperature is investigated using nonequilibrium molecular dynamics simulations from which the heat flux is also determined explicitly. The Ar-Fe intermolecular interactions induce the migration of fluid atoms into quasicrystalline interfacial layers adjacent to the walls, creating vacancies at the migration sites. This induces temperature discontinuities between the solidlike interfaces and their neighboring fluid molecules. The interfacial temperature difference and thus the heat flux decrease as the system equilibrates over time. The averaged interfacial thermal resistance R k,av decreases as the imposed wall temperature T w is increased, as R k,av ϰ T w −4.8 . The simulated temperature evolution deviates from an analytical continuum solution due to the overall system heterogeneity.

A thermal logic device based on fluid-solid interfaces

“…[23][24][25] Retaining the inert interfaces 2 and 4, as denoted in Fig. 1(a), but making interfaces 1 and 3 hydrophilic by imparting 6d charges to the corresponding walls, introduces asymmetry.…”

Heat conduction across a solid-solid interface: Understanding nanoscale interfacial effects on thermal resistance

“…20 The entire system is thereafter allowed to behave freely with constant volume and energy over the next 11 ns. All simulations used a timestep of 0.002 ps.…”

Lattice thermal conductivity of a silicon nanowire under surface stress

“…3,7 The phonon properties of a nanostructure, such as a nanowire, 8 can be tailored through a proper selection of acoustically mismatched materials. [9][10][11][12][13] The surface roughness of a nanowire can also significantly influence its thermal conductivity. 14,15 For instance, the room temperature phonon thermal conductivity has been reported to be reduced for roughened silicon nanowires to 1.6 W m À1 K À1 from the corresponding bulk value of 150 W m À1 K À1 (Ref.…”