Physically-based Modeling of Squeeze Film Damping by Mixed Level System Simulation

Schrag, G.; Voigt, Peter; Wachutka, G.

doi:10.1007/978-3-642-59497-7_159

Cited by 13 publications

(16 citation statements)

References 1 publication

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“…A similar approach was presented in Veijola et al (1995), but an equivalent circuit was constructed to solve the problem with a circuit simulation tool. In Schrag et al (2001), Sattler et al (2002), Sattler and Wachutka (2004), and Schrag and Wachutka (2004), a tilting perforated mirror was analyzed using a finite network method. Among papers belonging to the second category, there is Yang and Yu (2002), who used an equation similar to the PPR equation to build further reduced models.…”

Section: Reduced-dimension Numerical Methodsmentioning

confidence: 99%

“…Several analytic models (Skvor 1967;Veijola and Mattila 2001;Veijola et al 2002;Bao et al 2002Bao et al , 2003Homentcovschi and Miles 2004;Mohite et al 2005;Veijola 2006a, b), and dimension-reduction numerical models (Starr 1990;Veijola et al 1995;Schrag et al 2001;Sattler et al 2002;Yang and Yu 2002;Mehner et al 2003;Sattler and Wachutka 2004;Schrag and Wachutka 2004;Veijola 2007) have been published. In most of the publications, the verifications and the validity regime of applicable operation range are missing.…”

Section: Introductionmentioning

confidence: 97%

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Comparative numerical study of FEM methods solving gas damping in perforated MEMS devices

Pasquale

Veijola

2008

Microfluid Nanofluid

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Three different numerical strategies are presented for the estimation of the damping force acting on perforated movable MEMS dampers. Results from the 2D Perforated Profile Reynolds (PPR) method and the simplified 2D ANSYS method are compared with accurate full 3D flow simulations. Altogether, 32 different topologies are compared varying, e.g., the dimensions of the square damper and the square holes, and the number of holes. The case of uniform perforation and perpendicular motion is studied. Oscillation in the low frequency regime is assumed, that is, the compressibility and inertia of the gas are ignored in the study. While the PPR method is in good agreement with the 3D simulations, the forces given by the ANSYS method were considerably smaller. The reasons for this are studied, and a compact expression to explain the small forces is derived.

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Section: Reduced-dimension Numerical Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Comparative numerical study of FEM methods solving gas damping in perforated MEMS devices

Pasquale

Veijola

2008

Microfluid Nanofluid

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“…The methods available for analyzing high frequency flows incorporating effect of holes are very time consuming as explained in Refs. [12,14]. They also require special simulators to perform simulations.…”

Section: Introductionmentioning

confidence: 99%

“…However, they have taken perforation effect while modelling but their formula for squeeze film damping gives good results for small perforations. In another study aimed at modelling perforations in complex devices, Schrag and Wachutka [14] have proposed a mixed level scheme in which compact models that account for the flow through the holes and the edge effects are incorporated in a finite network (FN) model of Reynolds equation. Then, the discretized FN model is solved using a standard system simulator (e.g.…”

Section: Introductionmentioning

confidence: 99%

Analytical solution of the modified Reynolds equation for squeeze film damping in perforated MEMS structures

Pandey

Pratap

Chau

2007

Sensors and Actuators A: Physical

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“…The damping associated with the perpendicular movement of an oscillating structure is generally referred to as squeeze film damping and has been the subject of many previous investigations. [2][3][4][5][6] In these studies, it is commonly assumed that the surface area of the structure is much greater than the gap dimension and the system is adequately represented by the Reynolds equation. In an early analytical study, 2 viscous effects were included, but more recent MEMS devices have required consideration of rarefaction effects.…”

Section: Introductionmentioning

confidence: 99%

Nonplanar oscillatory shear flow: From the continuum to the free-molecular regime

Emerson

Stefanov

et al. 2007

Physics of Fluids

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The case of oscillatory cylindrical Couette gas flow has been used to investigate the effects of curvature and rarefaction on the dynamic velocity and shear stress profiles. In addition, Stokes' second problem for a curved surface has been extended to include the effects of slip. It is shown that curvature plays a more important role than slip in determining the penetration depth, but the effects of slip are enhanced if the surface is nonplanar. The current analysis for the oscillatory cylindrical Couette problem presents new analytical solutions in the slip-flow regime and the free-molecular regime. For both cases, direct simulation Monte Carlo data are in good agreement with the analytical solutions. To complete the study throughout the entire Knudsen regime, the direct simulation Monte Carlo method was used to predict the velocity and shear stress in the transition regime. There are marked differences between the solutions obtained for the inner and outer cylinders oscillating, especially at low frequencies. It is shown that if the Knudsen number is large ͑Ͼ1.0͒, the shear stress tends to the solution for the planar Couette case in the free-molecular regime and is essentially independent of the oscillatory frequency. Moreover, we show that the phenomenon of velocity inversion can occur for oscillatory flow provided the accommodation coefficient of the outer cylinder is small and the frequency is not too high.

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Physically-based Modeling of Squeeze Film Damping by Mixed Level System Simulation

Cited by 13 publications

References 1 publication

Comparative numerical study of FEM methods solving gas damping in perforated MEMS devices

Comparative numerical study of FEM methods solving gas damping in perforated MEMS devices

Analytical solution of the modified Reynolds equation for squeeze film damping in perforated MEMS structures

Nonplanar oscillatory shear flow: From the continuum to the free-molecular regime

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