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## Simulation Mechanical and Multiphysics

Active Contributor
Posts: 38
Registered: ‎09-11-2006

# Dictating symmetry in Fluid flow

463 Views, 2 Replies
06-21-2010 07:04 AM

I have not been able to find the proper documentation on how to tell ALGOR what surface is the symmetric surface.  I understand I can use a mirror plane for the results, but I think the solution is treating the symmetric surface as a wall.

I have told the mesher to exclude the symmetric surface from the boundary layer mesh, which allows it to have the right mesh geometry, but the velocity at the surface appears to be set to 0, is there anyway to adjust this setting?  Solving the solution this way allows me to run a finer mesh without the drawbacks of computation time.  Any input would be greatly appreciated.  (For instance, modeling the full geometry would result in a much more course mesh and would not result in any decrease in computation time, where as modeling 1/2 of the model along it's symmetric plane the same number of elements can be used for the same amount of computation time, but would give me a finer mesh)

Employee
Posts: 492
Registered: ‎03-25-2010

# Re: Dictating symmetry in Fluid flow

06-21-2010 07:41 AM in reply to: vex

Hi,

You just need to apply the proper prescribed velocity to the symmetry face. The direction normal to the face should be set to 0, and the two directions parallel to the face should not be set.

This is described in "Autodesk Algor Simulation > Setting Up and Performing the Analysis > Setting Up Part 2 > Fluid Flow > Loads and Constraints > Prescribed Velocity", then the paragraph "What Does a Prescribed Velocity Do?". See Table 1 and Figure 3 for an example.

Sincerely,
John Holtz, P.E.
Senior User Experience Designer, Simulation
Autodesk, Inc.

Current version of Mechanical & Multiphysics: 2013 SP1 (2013.01.00.0012 28-Jun-2012)
Active Contributor
Posts: 38
Registered: ‎09-11-2006

# Re: Dictating symmetry in Fluid flow

06-21-2010 07:44 AM in reply to: INACTIVE_AstroJohn

That's pretty simple.  Thanks for your help!