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Singular matrix and failed to find a solution

Posted Jan 27, 2010, 9:26 a.m. EST 2 Replies

Thanh Long Vu
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Hi everyone,
I just have a error like this when i increase the mesh

> ??? Java exception occurred:
> Exception:
> com.femlab.jni.FlNativeException: Singular matrix
> Messages:
> Singular matrix
>
> Stack trace:
> at umfpack.cpp, row 597, ()
> at com.femlab.solver.FlSolver.femStatic(Native Method)
> at com.femlab.solver.FemStatic.run(Unknown Source)
> at com.femlab.server.FlRunner.run(Unknown Source)
> at com.femlab.server.q.run(Unknown Source)
> at com.femlab.util.i.run(Unknown Source)
> at com.femlab.util.aa.run(Unknown Source)
>
> Error in ==> femsolver at 368
> solobj.smartRunner(report, loopTime);
>
> Error in ==> femstatic at 93
> varargout = femsolver(mfilename,'FemStatic',varargin{:});

And an other problem:
> Warning:
> Failed to find a solution:
> The relative error (0.044) is greater than the relative tolerance.
> Returned solution has not converged.

How can i solve this problem? anyone knows?
Thank u very much
Long
2 Replies Last Post Jun 23, 2010, 9:49 a.m. EDT
Leonardo Babun
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Posted: 1 decade ago Jan 27, 2010, 10:17 a.m. EST
Hi Long...This error is most related with the the geometry and the mesh...take care about to use objects with small geometries and meshed too big...It is important to find a proportional relation between both concepts. a good solution is to make a selective mesh by subdomains or boundaries.

Hope this help...

Leo

Hi Long...This error is most related with the the geometry and the mesh...take care about to use objects with small geometries and meshed too big...It is important to find a proportional relation between both concepts. a good solution is to make a selective mesh by subdomains or boundaries. Hope this help... Leo
Joseph Maduzia
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Posted: 1 decade ago Jun 23, 2010, 9:49 a.m. EDT
I actually get the singular matrix problem when I decrease my mesh size! My mesh isn't good enough for me to confidently use it, but I can't decrease my mesh size overall without getting the singular matrix error. I've tried meshing different sizes per subdowmain based on flow and HT gradients, but I still get the singular matrix problem with this...

Thank You,

Joe
I actually get the singular matrix problem when I decrease my mesh size! My mesh isn't good enough for me to confidently use it, but I can't decrease my mesh size overall without getting the singular matrix error. I've tried meshing different sizes per subdowmain based on flow and HT gradients, but I still get the singular matrix problem with this... Thank You, Joe

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