Surface effects on friction-induced fluid heating in nanochannel flows

Area of Science:

• Fluid dynamics
• Surface physics
• Nanoscale science

Background:

• Understanding friction-induced heating is crucial for microfluidic and nanoscale devices.
• Poiseuille flow at the nanoscale presents unique thermal phenomena.
• Surface interactions significantly influence fluid behavior at small scales.

Purpose of the Study:

• To elucidate the primary mechanisms of friction-induced fluid heating in nanoscale Poiseuille flows.
• To investigate the roles of internal fluid friction versus fluid-solid interface friction.
• To analyze the impact of external force and wall properties on temperature distribution.

Main Methods:

• Molecular dynamics simulations were employed to model liquid argon and helium.
• Nanoscale Poiseuille flow conditions were simulated.
• Temperature distributions and gradients were analyzed under varying external forces and wall conditions.

Main Results:

• Fluid heating is dominated by internal viscous friction at low external forces and no slip.
• At higher forces exceeding fluid-surface binding, interfacial friction becomes the dominant heating source.
• Non-identical walls induce asymmetric temperature gradients, which can reverse sign with changing dominant friction.

Conclusions:

• The mechanism of nanoscale fluid heating is dependent on the interplay between internal fluid viscosity and fluid-surface interactions.
• External force is a key parameter controlling the transition between different heating mechanisms.
• Tailoring wall properties and managing external forces can control thermal effects in nanoscale fluid systems.