Knudsen heat capacity

Gulru Babac*, Jason M. Reese

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

We present a "Knudsen heat capacity" as a more appropriate and useful fluid property in micro/nanoscale gas systems than the constant pressure heat capacity. At these scales, different fluid processes come to the fore that are not normally observed at the macroscale. For thermodynamic analyses that include these Knudsen processes, using the Knudsen heat capacity can be more effective and physical. We calculate this heat capacity theoretically for non-ideal monatomic and diatomic gases, in particular, helium, nitrogen, and hydrogen. The quantum modification for para and ortho hydrogen is also considered. We numerically model the Knudsen heat capacity using molecular dynamics simulations for the considered gases, and compare these results with the theoretical ones.

Original languageEnglish
Article number052002
Number of pages12
JournalPhysics of Fluids
Volume26
Issue number5
DOIs
Publication statusPublished - May 2014

Keywords

  • molecular dynamics
  • rarefied gas dynamics
  • heat capacity
  • thermal transpiration
  • diffusive transport
  • heat transfer
  • thermodynamics

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