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Problem about model convergence

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After changing the size of the model does not converge, how to solve this problem. For example: Change the model's unit from cm to m.


2 Replies Last Post 4 déc. 2017, 08:24 UTC−5

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Posted: 7 years ago 3 déc. 2017, 21:47 UTC−5

There is no problem with the convergence of the model before changing the size, and after changing the size, it always prompts "can not find the solution and reach the maximum number of Newton iterations. The returned result does not converge."

There is no problem with the convergence of the model before changing the size, and after changing the size, it always prompts "can not find the solution and reach the maximum number of Newton iterations. The returned result does not converge."

Jeff Hiller COMSOL Employee

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Posted: 7 years ago 4 déc. 2017, 08:24 UTC−5

Hello Shuo,

Each physics is different, so you may want to elaborate on what type of simulation you are doing, and ideally attach you model file.

To illustrate why changing the scale of the geometry can affect convergence, consider a fluid flow analysis: a flow that is laminar at the centimeter scale could be laminar at the meter scale it could be turbulent which would mean it would need to be solved using a different set of equations.

Best regards,

Jeff

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Jeff Hiller
Hello Shuo, Each physics is different, so you may want to elaborate on what type of simulation you are doing, and ideally attach you model file. To illustrate why changing the scale of the geometry can affect convergence, consider a fluid flow analysis: a flow that is laminar at the centimeter scale could be laminar at the meter scale it could be turbulent which would mean it would need to be solved using a different set of equations. Best regards, Jeff

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