Dissertation Defense: "Computation of Knudsen diffusivity in domains with boundary microstructure"

Abstract: In this dissertation we develop an analytical framework and numerical methods for the determination of the coefficient of self-diffusivity for the transport of a rarefied gas in channels, in the limit of large Knudsen number. We provide an effective method for determining the influence of channel surface microstructure on the value of diffusivity. We also show how characteristic numbers of the system, namely geometric parameters of the microstructure, the spectral gap of a Markov transition operator defined for a given microstructure, and the tangential momentum accommodation coefficient of a commonly used model of surface scattering, are related. Examples of micro-structures are investigated regarding the relation of these quantities numerically and analytically. 

Host: Renato Feres

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