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Solver issue in modified Application Example

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Hello everyone,

i am rather new to COMSOL and currently working with the Application Example for the Electrostatic Precipitator.

I loaded the given file and then tried some different parameters. I edited the values of the Global 'Parameters1' slightly and added a Value for the temperature. I used this parameter in every Temperature depended simulation.

Now when I try to compute the 'Corona and laminar Flow' simulation I’m getting an Error for X degrees of freedom for variables comp1.u and comp1.v.

X is always a number, but changes as I vary the Parameter list slightly.

Other discussions with this error message recommend checking the material parameters and the boundary conditions, but as I understand I didn't touch either and it worked before.

I would appreciate any help to solve this problem.


1 Reply Last Post Aug 17, 2023, 10:25 a.m. EDT

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Posted: 1 year ago Aug 17, 2023, 10:25 a.m. EDT

After a day of trial an error i have some updates. I turned the mesh a litte bit coarser, which helped the solver to some degree, but the average flow velocity still causes the problem when decreased to much. The same happen when i increase the electrodes potential. All other parameters do not influence the comupation process in a significant way.

Currently the last solving airflow was 0.5 m/s but i would like to simulate 0.1 m/s or at least 0.3 m/s. The elektric potential is not as important to me, but if there is a way to solve the problem with 30 kV instead of 20 kV i would gladly do it.

I would be very happy for any help on further solutions to this problem.

After a day of trial an error i have some updates. I turned the mesh a litte bit coarser, which helped the solver to some degree, but the average flow velocity still causes the problem when decreased to much. The same happen when i increase the electrodes potential. All other parameters do not influence the comupation process in a significant way. Currently the last solving airflow was 0.5 m/s but i would like to simulate 0.1 m/s or at least 0.3 m/s. The elektric potential is not as important to me, but if there is a way to solve the problem with 30 kV instead of 20 kV i would gladly do it. I would be very happy for any help on further solutions to this problem.

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