Gas Near a Wall: Shortened Mean Free Path, Reduced Viscosity, and the Manifestation of the Knudsen Layer in the Navier–Stokes Solution of a Shear Flow

  title={Gas Near a Wall: Shortened Mean Free Path, Reduced Viscosity, and the Manifestation of the Knudsen Layer in the Navier–Stokes Solution of a Shear Flow},
  author={Rafail V. Abramov},
  journal={Journal of Nonlinear Science},
  • R. Abramov
  • Published 9 January 2017
  • Physics
  • Journal of Nonlinear Science
For the gas near a solid planar wall, we propose a scaling formula for the mean free path of a molecule as a function of the distance from the wall, under the assumption of a uniform distribution of the incident directions of the molecular free flight. We subsequently impose the same scaling onto the viscosity of the gas near the wall and compute the Navier–Stokes solution of the velocity of a shear flow parallel to the wall. Under the simplifying assumption of constant temperature of the gas… 

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