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Failed to find consistent initial values.

Posted Nov 10, 2011, 5:05 p.m. EST Modeling Tools & Definitions, Parameters, Variables, & Functions Version 4.1 2 Replies

Yang Wei
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Hello,

I was doing a simulation about coupling two physics together by using the moving mesh. What I did is to run the solid mechanics first and stored the results. The laminar flow was then run by using the output from solid mechanics as the input. However, the solid mechanics part was fine but once I did laminar flow a error window was popped up.

=========================================
Failed to find consistent initial values.
Singular matrix.

There are 113 void equations (empty rows in matrix) for the variable Pump.p
at coordinates: (0.0145358,-0.0073668,0.001425), (0.0137255,-0.00590277,0.001425), (0.0124142,-0.0068996,0.001125), (0.0122855,-0.00665798,0.001125), (0.0122064,-0.00664936,0.001425), ...

There are 1074 degrees of freedom that do not occur in any equation (empty columns in matrix) for the variable Pump.p
at coordinates: (0.0145358,-0.0073668,0.001425), (0.0137255,-0.00590277,0.001425), (0.0124142,-0.0068996,0.001125), (0.0122855,-0.00665798,0.001125), (0.0122064,-0.00664936,0.001425), ...
Last time step is not converged.

=========================================

There was no errors relative to the moving mesh part so I supposed this part was okay. The problem might be the coupling between two physics.....


Anyone knows what happened?


Many thank for the help.



2 Replies Last Post Nov 12, 2011, 5:19 a.m. EST
Yang Wei
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Posted: 1 decade ago Nov 11, 2011, 6:17 a.m. EST
Any help?? ^_^
Any help?? ^_^
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago Nov 12, 2011, 5:19 a.m. EST
Hi

for me void equations rows are linked to incmplete BC definitions, there is not enough boundary conditions to give a unique solution, perhapsyou need to fix teabsolute pressure somewhere with a p=0 condition, i.e. on a point

PS I have not gone trough the full tread, its my first thoughts from your last input

--
Good luck
Ivar
Hi for me void equations rows are linked to incmplete BC definitions, there is not enough boundary conditions to give a unique solution, perhapsyou need to fix teabsolute pressure somewhere with a p=0 condition, i.e. on a point PS I have not gone trough the full tread, its my first thoughts from your last input -- Good luck Ivar

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