A three-dimensional quasi-static Stokes model, with a correction based on the kinetic theory of rarefied gas, is used to evaluate the damping forces exerted by gas flows on the moving surfaces of micromechanical structures in a wide range of pressures. Numerical results are compared with the experimental data collected on a silicon biaxial accelerometer in the continuum and transitional flow regimes. Furthermore, rarefied gas flows in ultra-thin film slider bearings are studied through a generalized Reynolds equation based on the linearized Boltzmann equation which holds for arbitrary Knudsen numbers. Since the generalized Reynolds equation is a flow rate-based model and is obtained by calculating the fundamental flows in the lubrication film (i.e., the Poiseuille and Couette flows), the plane Poiseuille-Couette flow problem between parallel plates has been preliminarly investigated. General boundary conditions of Maxwell's type have been considered by allowing for bounding surfaces with different physical properties.

On the application of the Boltzmann equation to the simulation of fluid structure interaction in MEMS

CERCIGNANI, CARLO;FRANGI, ATTILIO ALBERTO;FREZZOTTI, ALDO;GHIROLDI, GIAN PIETRO;GIBELLI, LIVIO;LORENZANI, SILVIA
2008

Abstract

A three-dimensional quasi-static Stokes model, with a correction based on the kinetic theory of rarefied gas, is used to evaluate the damping forces exerted by gas flows on the moving surfaces of micromechanical structures in a wide range of pressures. Numerical results are compared with the experimental data collected on a silicon biaxial accelerometer in the continuum and transitional flow regimes. Furthermore, rarefied gas flows in ultra-thin film slider bearings are studied through a generalized Reynolds equation based on the linearized Boltzmann equation which holds for arbitrary Knudsen numbers. Since the generalized Reynolds equation is a flow rate-based model and is obtained by calculating the fundamental flows in the lubrication film (i.e., the Poiseuille and Couette flows), the plane Poiseuille-Couette flow problem between parallel plates has been preliminarly investigated. General boundary conditions of Maxwell's type have been considered by allowing for bounding surfaces with different physical properties.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11311/547025
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