3 Replies Latest reply on Jul 9, 2013 11:24 AM by Jared Conway

Unresolved Boundary Layer Condition

Wendell Su Jul 3, 2013 4:29 PM

I am designing a microfluidic chip with a number of inlets and outlets that all connect to a common chamber. One particular inlet and the outlet have serpentine channels linking them to the common chamber. When I try define boundary conditions (inlet volume flow/environmental pressure) on those particular ports I get the "unresolved boundary condition" warning when I run the simulation. I do not have this type of trouble when the boundary conditions are set on the other inlets and I use one of the inlets as the outlet,and the simulation works fine. The designs of the inlet/outlet are all exactly the same. Is there a particular reason why some inlets work and some don't? Does it have to do with the serpentine channels? Any help is appreciated, thanks.

Wendell

Re: Unresolved Boundary Layer Condition

Jared Conway Jul 7, 2013 11:55 PM (in response to Wendell Su)

Sounds like a model issue or mesh issue. Have you tried setting up a simplified model? Have you tried improving the mesh? Posting the model might help as would checking the customer portal kb.

Here are some suggestions on things to check in your model

http://www.hawkridgesys.com/blog/flow-simulation-4-starting-flow-simulation-analysis/
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- Re: Unresolved Boundary Layer Condition
  
  Wendell Su Jul 9, 2013 10:25 AM (in response to Jared Conway)
  
  Thanks for the help. I simplified my model by taking out the snouts that increase the volume of the inlet and setting boundary conditions directly at the inlet. Doing that made the simulation run fine. Fortunately the presence of the snout in my configuration doesn't factor into the dynamics of the chip so the simplified model works.
  
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  - Re: Unresolved Boundary Layer Condition
    
    Jared Conway Jul 9, 2013 11:24 AM (in response to Wendell Su)
    
    if you want to post the model that has the issue, i'm sure someone can find the cause of the problem.
    
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