AVS 59th Annual International Symposium and Exhibition
    MEMS and NEMS Tuesday Sessions
       Session MN-TuP

Paper MN-TuP1
Tangential Momentum Accommodation Coefficients in Coated Microtubes

Tuesday, October 30, 2012, 6:00 pm, Room Central Hall

Session: MEMS and NEMS Poster Session
Presenter: M. Wüest, INFICON Ltd, Liechtenstein
Authors: M. Hadj Nacer, Aix-Marseille Université, Ecole Polytechnique Universitaire de Marseille, France
I. Graur, Aix-Marseille Université, Ecole Polytechnique Universitaire de Marseille, France
P. Perrier, Aix-Marseille Université, Ecole Polytechnique Universitaire de Marseille, France
J.G. Méolans, Aix-Marseille Université, Ecole Polytechnique Universitaire de Marseille, France
M. Wüest, INFICON Ltd, Liechtenstein
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The experimental setup based on the constant volume technique is developed to measure the mass flow rate through microtubes under isothermal stationary flow conditions. Four different working gases (helium, nitrogen, argon and carbon dioxide), and two surface materials (Stainless Steel and Sulfinert) are considered.

The Knudsen number calculated for the experimental conditions varies from 0.0001 (hydrodynamic regime) to 0.1 (slip regime). In this range the approach based on the analytical solution of the Stokes equation subjected to the first order velocity slip boundary condition is used. The velocity slip coefficient and the Tangential Momentum Accommodation Coefficient (TMAC) are extracted from the experimental data of the mass flow rate using their analytical expressions.

The results are summarized in the tables representing the accommodation coefficients for the corresponding gas-surface material combinations. The influence of the molecular mass on the tangential momentum accommodation coefficient is discussed.