Menu

Discussion Forum

New Discussion
Filter

Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Squeeze Film Damping and Fluid Flow Deformation issues

Posted Jul 22, 2014, 7:26 p.m. EDT MEMS & Nanotechnology, MEMS & Piezoelectric Devices, Structural Mechanics Version 4.4 0 Replies

Logan Garbarini
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

I have been trying to simulate a micrometer scale (40 um x 16 um x 0.2 um) structure in laminar flow so I can calculate the forces and deformation due to movement towards and away from a surface. However, when I follow the same procedure as the "Squeezed-Film Gas Damping in an Accelerometer" example, I get my deformation value as 2E-15 m. I was expecting something in the order of 5 nanometers (1E-9) range so something is clearly off. All I did to modify the procedure outlined in the example was I replaced the acceleration value with 0.1m/s^2 and changed the fluid properties to those of water as opposed to air.

My laminar fluid flow has similar symptoms:
While I was still struggling with the MEMS module I tried to model the same structure in laminar flow (Based on "Obstacle in a Fluid" example) with an inlet velocity of 4E-7m/s and outlet pressure of 0 and I was having similarly small values of deformation at the end of the beam, 1E-12 m ballpark.

I know these are different modules since the symptoms are similar I thought I might combine them.
Here are the basics of my setup:
The beam is only constrained on one end with a fixed constraint.
The whole object is selected as "Prescribed Deformation'








0 Replies Last Post Jul 22, 2014, 7:26 p.m. EDT
COMSOL Moderator

Hello Logan Garbarini

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content