Title
Knudsen Diffusivity In Random Billiards: Spectrum, Geometry, And Computation
Abstract
We develop an analytical framework and numerical approach to obtain the coefficient of self-diffusivity for the transport of a rarefied gas in channels in the limit of large Knudsen number. This framework provides a method for determining the influence of channel surface microstructure on the value of diffusivity that is particularly effective when the microstructure exhibits relatively low roughness. This method is based on the observation that the Markov transition (scattering) operator determined by the microstructure, under the condition of weak surface scattering, has a universal form given, up to a multiplicative constant, by the classical Legendre differential operator. We also show how characteristic numbers of the system-namely, geometric parameters of the microstructure, the spectral gap of a Markov operator, and the tangential momentum accommodation coefficient of a commonly used model of surface scattering-are all related. Examples of microstructures are investigated to illustrate the relation of these quantities numerically and analytically.
Year
DOI
Venue
2021
10.1137/20M1349552
SIAM JOURNAL ON APPLIED DYNAMICAL SYSTEMS
Keywords
DocType
Volume
random billiards, Knudsen diffusivity, Markov chain central limit theorem, spectral gap
Journal
20
Issue
ISSN
Citations 
3
1536-0040
0
PageRank 
References 
Authors
0.34
0
3
Name
Order
Citations
PageRank
Chumley Timothy100.34
R. Feres201.35
German Luis Alberto Garcia300.34