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How to approach reduction of relative error in magnetic field?

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Hi, I am a researcher who have few experience in COMSOL.
I try to design a cold crucible for induction melting of titanium ingot
My model represents a quarter of full geometry.
To check convergence in magnetic field, I just added magnetic field physics except for heat transfer.
I've calculated my model several times but I couldn't figure out these error messages

"Failed to find a solution.
The relative error (2.4e+008) is greater than the relative tolerance.
Returned solution is not converged."

I used direct solver (default) and then the log were shown as down below

Stationary Solver 1 in Solution 1 started at 2-1-2016 02:00:31.
Linear solver
Number of degrees of freedom solved for: 5175615.
Nonsymmetric matrix found.
Scales for dependent variables:
Magnetic vector potential (comp1.A): 0.059
Coil potential (comp1.mf.VCoil): 0.018
Coil voltage (comp1.mf.stcd1.stcdp1.VCoil_ode): 1
Coil voltage (comp1.mf.stcd2.stcdp1.VCoil_ode): 1
Coil voltage (comp1.mf.stcd3.stcdp1.VCoil_ode): 1
Coil voltage (comp1.mf.stcd4.stcdp1.VCoil_ode): 1
Coil voltage (comp1.mf.stcd5.stcdp1.VCoil_ode): 1
Sparse null-space function used.
Iter SolEst Damping Stepsize #Res #Jac #Sol LinErr LinRes
1 0.91 1.0000000 0.91 1 1 1 2.4e+008 5.8e-005
Stationary Solver 1 in Solution 1: Solution time: 36964 s (10 hours, 16 minutes, 4 seconds)
Physical memory: 255.56 GB
Virtual memory: 486.7 GB

Any idea to rescue me?

Best regards.

p.s. I attach my model by split compression because of file size error (only 6.4MB!)
but only allowed file could be attached so I tried to change extension of v3-1 file. (.z01 is not allowed)
so if you were going to check the model, please change the extension of "v3-1" file from zip to z01
and then change the file name from v3-1 to v3 (in case of split compression, the file names should be exactly same each other). Thank you!


0 Replies Last Post 1 janv. 2016, 23:56 UTC−5
COMSOL Moderator

Hello Hyunjae Lee

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