CFD error message (about convergence)

[ryu]

Hello
Analyzing, I met warning message.
But I don’t know what to means.
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**** Maximum attempts exceeded


**** The solution did not meet convergence criteria,
try the following options:
(1) reduce the loading
(2) relax the convergence criterion
(3) increase the number of iterations
(4) use custom time with different value of increment
(5) try transient fluid-flow analysis (flow04)
(6) contact ALGOR service at service@Algor.com
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please answer me, to do setting option or how to solution

[PipePakPat]

ryu@daoudata.co.kr,

The message you received indicates that the process used an iterative solving technique and could not converge on a solution within the iteration limit. The processor then made 6 recommendations. The only revision to these six recommendations that I would offer is the sixth, which should suggest to contact for technical support. Otherwise, the message is generic. This issue may require examination by technical support to make relevant suggestions.

Pat Tessaro, P.E.
Autodesk Inc.

[Joey.X]

Except above suggestions, the typical modeling issues for the fluid flow divergence or oscillation are

- Use steady state solve true unsteady problem (such as vortex shedding problem);

- Illegal boundary conditions

- Boundary layer mesh at flow inlets and outlets

- Forget turning on turbulence for turbulence flow(user needs to check the Reynolds number)

- Poor mesh (usual too coarse) with no or few interior fluid nodes in narrow channels.