Free Surface , errors (Please Help ASAP)

hossein_sml · March 30, 2016, 09:32

Hi

I am modeling a free surface problem. in middle of simulation (after 2700 steps) it has been stopped and the error is:

| ERROR #004100018 has occurred in subroutine FINMES. | | Message: | | Fatal overflow in linear solver.

as previous guides, I reduced the timestep to 1e-4 and the error occurred.

I reduced timestep more up to 1e-5, this time new error occured:

Error #001100279 has occurred in subroutine ErrAction. Message :Floating point exception :Over flow

Why this is happening in middle of simulation?

ghorrocks · March 30, 2016, 17:36

The FAQ on this topic (http://www.cfd-online.com/Wiki/Ansys...do_about_it.3F) recommends a lot more than just adjusting time step. There are many other things to look at.

hossein_sml · March 31, 2016, 05:56

As I told the simulation have been progressed up to 2700 iteration with good convergence.
- Setup is Ok
- Initial Condition has no problem
- I am using Double precision

Only 2 parameter remains:
1- Time Step
2- Mesh quality

About mesh as I explained the simulation has been progressed good with good convergence, and nothing strange is happening in that specific time.

How can I find the problem?

ghorrocks · March 31, 2016, 08:18

Have a close look at the results file from a short time before the crash. I suspect you will find a surface wave has reached somewhere important (eg a boundary or a region with poor mesh quality).

If you have checked this please attach an image of your geometry and mesh, an image of what you simulation results looks like shortly before it crashes and your CCL.

March 30, 2016, 09:32	Free Surface , errors (Please Help ASAP)	#1
hossein_sml New Member hossein Join Date: May 2012 Posts: 28 Rep Power: 13	Hi I am modeling a free surface problem. in middle of simulation (after 2700 steps) it has been stopped and the error is: \| ERROR #004100018 has occurred in subroutine FINMES. \| \| Message: \| \| Fatal overflow in linear solver. as previous guides, I reduced the timestep to 1e-4 and the error occurred. I reduced timestep more up to 1e-5, this time new error occured: Error #001100279 has occurred in subroutine ErrAction. Message :Floating point exception :Over flow Why this is happening in middle of simulation?

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March 30, 2016, 17:36		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,719 Rep Power: 143	The FAQ on this topic (http://www.cfd-online.com/Wiki/Ansys...do_about_it.3F) recommends a lot more than just adjusting time step. There are many other things to look at.

March 31, 2016, 05:56		#3
hossein_sml New Member hossein Join Date: May 2012 Posts: 28 Rep Power: 13	As I told the simulation have been progressed up to 2700 iteration with good convergence. - Setup is Ok - Initial Condition has no problem - I am using Double precision Only 2 parameter remains: 1- Time Step 2- Mesh quality About mesh as I explained the simulation has been progressed good with good convergence, and nothing strange is happening in that specific time. How can I find the problem?

March 31, 2016, 08:18		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,719 Rep Power: 143	Have a close look at the results file from a short time before the crash. I suspect you will find a surface wave has reached somewhere important (eg a boundary or a region with poor mesh quality). If you have checked this please attach an image of your geometry and mesh, an image of what you simulation results looks like shortly before it crashes and your CCL.