System Divergence over Maximum Tolerance

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Andre
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Joined: 09 Jun 2021, 19:05
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System Divergence over Maximum Tolerance

Post by Andre »

Hi there,

I am trying to get my system to converged however I keep getting the error over maximum tolerance.

In my sif file I changed both the below value to get greater convergence values.

Steady State Convergence Tolerance = 1.0e-10
Nonlinear System Convergence Tolerance = 1.0e-9
Linear System Convergence Tolerance = 1.0e-12
Linear System ILUT Tolerance = 1.0e-3

Does something else need to be done in order to get the system to keep doing the calculations.
kevinarden
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Joined: 25 Jan 2019, 01:28
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Re: System Divergence over Maximum Tolerance

Post by kevinarden »

Convergence to a tolerance is more likely to happen with a larger number not a smaller number. However the smaller the number the more accurate the answer. So;

Steady State Convergence Tolerance = 1.0e-10
Nonlinear System Convergence Tolerance = 1.0e-9
Linear System Convergence Tolerance = 1.0e-12
Linear System ILUT Tolerance = 1.0e-3

Is a very accurate solution but more difficult to converge on than say;

Steady State Convergence Tolerance = 1.0e-5
Nonlinear System Convergence Tolerance = 1.0e-5
Linear System Convergence Tolerance = 1.0e-7
Linear System ILUT Tolerance = 1.0e-2

Which is much easier to converge on, but not as accurate as the first one, since the convergence tolerance is the second example is much larger than the first.
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