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Singular matrix and failed to find a solution

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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 23 giu 2010, 09:49 GMT-4

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Posted: 1 decade ago 27 gen 2010, 10:17 GMT-5
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

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Posted: 1 decade ago 23 giu 2010, 09:49 GMT-4
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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