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Old   April 27, 2020, 13:00
Default Fatal overflow in linear solver
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I simulate a wave maker flume...
But when I define the Gravity in y-direction as a expression an error occur...
It's a simple expression G=0.1*g
I've search web for this error "Fatal overflow in linear solver"...
But I didn't get result...
I'm really confused...
Time step or mesh size is not the problem...
I change Allocate memory from 1 to 1.4...
I need help...
Wave-Maker-Theory.txt
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Old   April 27, 2020, 15:37
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I see that you use VOF. Free surface aligned to partition boundary can cuse divergence.
Try to set solver to serial mode or manualy set partitioning to ensure that free surface is not coincident with partition boundary.
Fatal overflow in linear solver occur when execute solution in parallel
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Old   April 27, 2020, 19:15
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There is an FAQ on this error: https://www.cfd-online.com/Wiki/Ansy...do_about_it.3F

In your case you will need to do some basic debugging.

Are you sure your mesh motion is correct? See FAQ for tips: https://www.cfd-online.com/Wiki/Ansy..._went_wrong.3F

Where did you get your time step size from? I bet you guessed it, and I bet your guess is wrong. Try a smaller time step.
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Old   May 3, 2020, 16:49
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Quote:
Originally Posted by karachun View Post
I see that you use VOF. Free surface aligned to partition boundary can cuse divergence.
Try to set solver to serial mode or manualy set partitioning to ensure that free surface is not coincident with partition boundary.
Fatal overflow in linear solver occur when execute solution in parallel
Thank you...It solve...
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Old   May 3, 2020, 16:52
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Quote:
Originally Posted by ghorrocks View Post
There is an FAQ on this error: https://www.cfd-online.com/Wiki/Ansy...do_about_it.3F

In your case you will need to do some basic debugging.

Are you sure your mesh motion is correct? See FAQ for tips: https://www.cfd-online.com/Wiki/Ansy..._went_wrong.3F

Where did you get your time step size from? I bet you guessed it, and I bet your guess is wrong. Try a smaller time step.
No....I checked the mesh...it's ok...Time step is T/200 according to paper....Thank you for your attention
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Old   May 3, 2020, 19:26
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Quote:
Originally Posted by pashazanousi View Post
Time step is T/200 according to paper....
If you want to be sure - check case with T/400, this will be your timestep convergence study. If nothing changed then you can be sure. Many things like mesh density, domain size, timestep, residuals are varying from problem to problem.
Never thrust papers or folks that say that some setting value is 100% enough. Often you can get advice about good setting values you can start with. Only convergence check (mesh convergence, timestep convergence, residual convergence) can answer this question.
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Old   December 22, 2020, 12:09
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i tried to do a Fluid-Structure Transient Simulation....
But I received the below image error
Untitled.jpg
I do tutorial oscillation plate...But I don't know what this error mean?
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Old   December 22, 2020, 17:11
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Please start a new thread for a new question in future.

The error message is very clear. In the ANSYS Mechanical side of things an element has become highly distorted and the solver failed. You are going to have to do something to stop the excessive distortion. Look at the distorted elements in the ANSYS Mechanical post processor to find the problem element.
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