Unstable solution in PDE System

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Hi,

I have a problem with a system of differential equations in which one variable has an unstable solution.

I suspect this instability is because the problem is advective and with FEM advective problems are usually unstable. However, I find it strange that COMSOL does not have a stabilization system. Is there any way to stabilize the solution?

In one of the scientific articles that I am using as a basis for this work they mention the use of an "orthogonal collocation method" as a variant of the FEM that allows a stable solution. Is there a possibility to solve the problem using this method?

Couldo someone help me with this issue ?

Thank you for your attention.

Best,


2 Replies Last Post Jul 23, 2024, 1:40 p.m. EDT
Magnus Ringh COMSOL Employee

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Posted: 4 months ago Jul 11, 2024, 2:20 a.m. EDT

Hi Andres,

It's hard to say what's going on without seeing the model. I suggest that you contact COMSOL Support for assistance. That said, COMSOL Multiphysics includes several stabilization measures for convection- or advection-dominated equations. See the "Numerical Stabilization" section in the COMSOL Multiphysics Reference Manual for more information.

Best regards, Magnus

Hi Andres, It's hard to say what's going on without seeing the model. I suggest that you contact COMSOL Support for assistance. That said, COMSOL Multiphysics includes several stabilization measures for convection- or advection-dominated equations. See the "Numerical Stabilization" section in the *COMSOL Multiphysics Reference Manual* for more information. Best regards, Magnus

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Posted: 3 months ago Jul 23, 2024, 1:40 p.m. EDT

Hi Magnus,

Thank you very much for this information.

Best, Andres

Hi Magnus, Thank you very much for this information. Best, Andres

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