Why is my COMSOL solution not converging?

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A second-year student is experiencing convergence issues while using COMSOL to solve problems with the incompressible Navier-Stokes model. The error message indicates that the relative error exceeds the set tolerance, preventing a converged solution. Despite attempts to adjust iterations, tolerance, and degrees of freedom through remeshing, the problem persists. Another user suggests that the issue may stem from pressure calculations in the Navier-Stokes physics, recommending that the student uncheck "p" in the "Solve for" section of the Solver Parameters. After some clarification, the student finds the option in the Solver Manager, successfully resolving the convergence issue.
yaelgo
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Hello,
I'm a 2nd year student, and I'm trying to get to know COMSOL. I'm starting off by solving simple problems with the incompressible Navier-Stokes model, but I keep having trouble with the convegence of the solution.
I keep getting the following error:

"Failed to find a solution:
The relative error is greater than the relative tolerance.
Returned solution has not converged."

I've tried to solve many problems, but it gives me the same error over and over again.
I've changed the number of iterations, the tolerance and the DOF by remeshing, but nothing seems to help.


If someone here has a usefull advice, I would really appreciate it.

Thanks,
Yael.
 
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I had the same problem. Comsol has a problem with pressure calculations in Navier-Stokes physics. You have to uncheck "p" on "Solve for" card in Solver Parameters.
 
Thank you!
but I don't really understand what you mean - I can't see "solve for" in the solver parameters.
could you be more specific? what solver are you using?

Thanks,
Yael.
 
Sorry, my fault - it's in Solver Manager.
 
it works! thanks :)
 

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