Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

error

Please login with a confirmed email address before reporting spam

i was doing the example given on cylinder flow.i did all steps as explain their,no change.But on solving i got an error


" Error:
Failed to find a solution:
No convergence, even when using the minimum damping factor.
Returned solution has not converged."

i am new with this software. please suggest me a way to remove this error.

please suggest.

3 Replies Last Post 29 giu 2010, 02:23 GMT-4

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 11 giu 2010, 09:52 GMT-4
If you get this error, there must be something wrong with the Boundary Conditions you have specified, double check the boundary conditions.

You can find the Error message and explanation for the same in COMSOL help. I copied the same below:

"No convergence, even when using the minimum damping factor" -The nonlinear solver reduced the damping factor below the minimum value allowed. The solver reduces the damping factor each time a computed step did not lead to a decrease in the error estimate. Make sure the model is well-posed, in particular that there are enough equations and boundary conditions to determine all degrees of freedom. If the model is well-posed, it should have one or more isolated solutions. In that case, the error is probably due to the initial guess being too far from any solution.

Regards,
AndyT
If you get this error, there must be something wrong with the Boundary Conditions you have specified, double check the boundary conditions. You can find the Error message and explanation for the same in COMSOL help. I copied the same below: "No convergence, even when using the minimum damping factor" -The nonlinear solver reduced the damping factor below the minimum value allowed. The solver reduces the damping factor each time a computed step did not lead to a decrease in the error estimate. Make sure the model is well-posed, in particular that there are enough equations and boundary conditions to determine all degrees of freedom. If the model is well-posed, it should have one or more isolated solutions. In that case, the error is probably due to the initial guess being too far from any solution. Regards, AndyT

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 11 giu 2010, 10:17 GMT-4
did you define a step inflow boundary function? (step function)
did you define and select the inlet and outlet boundary conditions correctly?
did you define a step inflow boundary function? (step function) did you define and select the inlet and outlet boundary conditions correctly?

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 29 giu 2010, 02:23 GMT-4
i think we have to define pressure at atleast one point for the solution to converge.
i think we have to define pressure at atleast one point for the solution to converge.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.