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Solver settings study step

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Hi

I'm using a stationary study for my problem in v4.1. When the Dependent Variable in solver settings was set to "defined by study step- step 1:stationary", the solution was not converging. But when I set the same to "defined by study step: user defined" the solution converges. Can anyone point out the logic behind this change affecting the convergence of the solution.
Thanks in advance.

Rahul

2 Replies Last Post 20 apr 2011, 03:27 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 20 apr 2011, 03:12 GMT-4
Hi
if I understand you well, you are changing the initial conditions (?) for your solver, this can indeed give a better starting point and allow the solver to find a solution (particularly the iterative ones)

--
Good luck
Ivar
Hi if I understand you well, you are changing the initial conditions (?) for your solver, this can indeed give a better starting point and allow the solver to find a solution (particularly the iterative ones) -- Good luck Ivar

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Posted: 1 decade ago 20 apr 2011, 03:27 GMT-4
Thanks for the reply Ivar.

But the initial conditions remained the same for both the cases i have described. The only change I made was the study step for dependent variable.
For your information, I had set the inital values for the problem as the velocities that are present in the actual flow itself, and not the defult value of zero, anticipating that it will help in better convergence.
I got the solution, but I couldn't understand the logic. If you can help me out, I will be thankful.

Regards
Rahul
Thanks for the reply Ivar. But the initial conditions remained the same for both the cases i have described. The only change I made was the study step for dependent variable. For your information, I had set the inital values for the problem as the velocities that are present in the actual flow itself, and not the defult value of zero, anticipating that it will help in better convergence. I got the solution, but I couldn't understand the logic. If you can help me out, I will be thankful. Regards Rahul

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