I am trying with solid model, so do i get any help in this. Section 4 calculates the squeeze-film damping using the present models, and compares the calculated results with the FEM results and the experimental data [ 21 ]. However, there is a clear discrepancy between the FEM model and the present model at large perforation ratios. Can please send me some link for 2-way FSI problem, for my help. FLUID elements are used to model the hole regions. Hot Topics 1 RGP table for supercritical, gas and liquid phase 2 problem with units not matching with initialized data? You can’t do 2-way FSI on a Student license. The fluid domain is modeled by overlaying FLUID elements on the moving surface of the structure i.

This first approach was followed by Skvor [ 8 ], Bao et al. Analysis Settings and Options. This Weeks High Earners peteroznewman 65 abenhadj 56 rwoolhou 46 jj77 33 tsiriaks 27 SandeepMedikonda 23 kkanade 20 Aniket 10 ahmadzaki 9 sharvey 9. Support Center Support Center. The perforated rectangular plate is excited by an electrostatic force. View the messages in mechanical editor for more detail”. The torsion plate is asymmetric with respect to the rotation axis. Therefore, the fluid adds both stiffening and damping to the system.

The microplate is operated in normal direction to the substrate. A complex transient analysis is performed for a rectangular top plate fixed squeezd two ends with a hole in the center.

Popular Tags fluent fluid-dynamics structural-mechanics ansys general cfd udf workbench 99 asc 98 sqqueeze 91 mechanical 83 mesh 83 apdl 78 cfx 72 maxwell 67 hfss 64 meshing 63 student 51 spaceclaim 47 static-structural A previous modal analysis indicated that the pertinent eigenfrequency was kHz.

squeeze film analysis

To examine the validity of the present model over a wide range of frequency, we compare the damping torques and the spring torques obtained by the present model and the FEM model in the range from 1 kHz to MHz. If the fluid is air at atmospheric pressure 1. A schematic drawing of a perforated torsion microplate supported by two torsion beams. At high frequencies, the fluid compresses before it can escape.


Squeeze film damping — CFD Online Discussion Forums

One is the air damping. The damping obtained by the experimental results including the two damping can be expressed by:. L m po is the mean free path of the fluid at the fjlm pressure P 0and L 0 is anxys mean path at reference pressure P 0. This paper is based on the second approach. An analytical formula and FEM simulations for the viscous damping of a periodic perforated MEMS microstructure outside the lubrication approximation.

The phase shift between the pressure and the velocity is caused by compression of the fluid. For convenience, we introduce the follow nondimensional variables:. The purpose of the analysis is to compute the equivalent squeeze stiffness and damping coefficient for an assumed uniform plate velocity. For the present model, we varied perforation ratios from 0. The FEM results in this paper are obtained by using the ansyw approach.

Obviously, the discrepancy between the FEM model and the suqeeze model increases as the perforation ratio increases. But while solving coupled system, I am getting error ” update failed for solution component in system coupling.

The total damping is calculated by multiplying the damping due to the single cell by the total number of cells.

Are you going to build the 2-way FSI to solve for the velocity and film thickness as a function of time? The main reason is as follows: The previous works presented by Bao et al.


Displacement and pressure results at the bottom of the top plate on the circumference of the hole are shown in Figure 1. Direct simulation of such structures with 3-D FEM tools is dampimg consuming and non-transparent [ 718 ]. In the type II device, the squeeze-film thickness can be expressed as:.

Abstract Squeeze-film damping plays a significant role in the performance of micro-resonators because it determines their quality factors. Also shown in the same figure are the results obtained by the present model with the effective length and width.

Squeeze-film damping plays a significant role in the performance of micro-resonators because it determines their quality factors.

Squeeze Film Analysis

The accuracy of the model is verified by comparing its results with the finite element method FEM results and the experimental results available in the literature.

In the modal projection method, the FLUID elements must lie on the surface of the structural mesh. TRANS transducer elements are created between the plates.

Proposed model The modified Reynolds equation presented by Pandey et al. If you create a 2-way FSI transient model, you can simulate directly the motion of the moving structure. Also shown in the same figures are the analytical results obtained by the present model.

The applied voltage is shown in Figure 1.