CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > CFX

Stopped in routine ENFORCE_BOUNDS

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 22, 2010, 11:36
Default Stopped in routine ENFORCE_BOUNDS
  #1
Senior Member
 
Join Date: Mar 2009
Posts: 138
Rep Power: 17
camoesas is on a distinguished road
Hello Everybody,

Briefly before Christmas I have a CFD Problem...
Maybe anybode can help me:

I am doing a transient simulation with cavitation. First I have made a transient simulation with cavitation turned off as initial guess. Now I have turned on cavitation and the solver explodes after a few Iterations. I get pressure values of about 300 bar, which causes my solver to abort.
See the Outfile Below:

Quote:
Slave: 3
Slave: 3 Fatal bounds error detected
Slave: 3 ---------------------------
Slave: 3 Variable: Fluid 1.Density
Slave: 3 Locale : Innen
Parallel run: Received message from slave
-----------------------------------------
Slave partition : 3
Slave routine : ErrAction
Master location : RCVBUF,MSGTAG=1022
Message label : 001100279
Message follows below - :

+--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine ErrAction. |
| Message: |
| Stopped in routine ENFORCE_BOUNDS |
| |
| |
| |
| |
| |
+--------------------------------------------------------------------+
+--------------------------------------------------------------------+
| An error has occurred in cfx5solve: |
| |
| The ANSYS CFX solver exited with return code 1. No results file |
| has been created. |
+--------------------------------------------------------------------+
End of solution stage.
+--------------------------------------------------------------------+
| The following transient and backup files written by the ANSYS CFX |
| solver have been saved in the directory |
| D:\kavitation_01_004: |
| |
| 1353_full.trn |
+--------------------------------------------------------------------+

+--------------------------------------------------------------------+
| The following user files have been saved in the directory |
| D:\kavitation_01_004: |
| |
| mon |
+--------------------------------------------------------------------+

This run of the ANSYS CFX Solver has finished.
Some Iterations before I got this Strange Notice:

Quote:
Parallel run: Received message from slave
-----------------------------------------
Slave partition : 3
Slave routine : EX_TABLE
Master location : End of Continuity Loop
Message label : 009100008
Message follows below - :
+--------------------------------------------------------------------+
| ****** Notice ****** |
| While evaluating Fluid 1.Temperature, |
| Absolute Pressure |
| went outside of its upper limit. Its maximum value was |
| 3.5814E+07. The bounds error was handled by extrapolation. |
| If this situation persists, consider increasing the table range. |
+--------------------------------------------------------------------+

Some Details for my Case:

- reference pressure: 0 atm
- timestep: 5.5e-5 s
- inlet: total pressure
- outlet1: opening
- outlet2: pressure outlet


Any Hints appreciated! Thanks in advance

Simon

More Details required?
camoesas is offline   Reply With Quote

Old   December 22, 2010, 18:21
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,665
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
Your simulation is not converging well. Need to improve the numerical stability - smaller timesteps, better mesh quality and check the physics.
ghorrocks is offline   Reply With Quote

Old   December 23, 2010, 07:11
Default
  #3
Senior Member
 
Join Date: Mar 2009
Posts: 138
Rep Power: 17
camoesas is on a distinguished road
HI Glenn,

I have double checked the mesh quality, it is quite well:
Minimum Angle > 27°
Determinant > 0.5

I decrease the timestep to nanoseconds (which is a valuable size for cavitation problems) and see after christmas if it helped.

Here some details for my cavitation model:
- Rayleigh Plesset
- Mean Diameter: 2e-6m
- Saturation Pressure: 0.02 bar

Merry Christmas!
camoesas is offline   Reply With Quote

Old   December 23, 2010, 07:21
Default
  #4
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,665
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
Mesh quality requirements are different for different physics models. The rules of thumb for single phase flow are often not appropriate for multi phase flow. I would spend some time to get the mesh as good as you can in the area of cavitation as it will pay dividends with improved convergence, better accuracy and reduced run time.

I would use adaptive time stepping to let it find its own time step size.
ghorrocks is offline   Reply With Quote

Old   January 12, 2011, 03:57
Default
  #5
Senior Member
 
Join Date: Mar 2009
Posts: 138
Rep Power: 17
camoesas is on a distinguished road
Hello Everybody and a Happy new Year!

I´ve got my case running, it was a false Expert Parameter Setting, I had:
solve volfrc = f

Setting this parameter to true, keeps the solver running. But Convergence is still bad.

Anyway now I am facing a real annoying problem:
My outfile clearly states to write Pressure to Transient file:

Code:
     TRANSIENT RESULTS: Transient Results 1
       File Compression Level = Default
       Include Mesh = No
       Option = Selected Variables
       Output Variables List = Fluid 1.Density,Fluid 1.MassTransfer,Fluid \
         1.Velocity u,Fluid 1.Velocity v,Fluid 1.Velocity w,Fluid 2.Volume \
         Fraction,MassTransfer,Pressure,Total Pressure
But in Post I cant read pressure data, all other variables are available!

Has anybody a solution for this stupid problem?!

Thanks
camoesas is offline   Reply With Quote

Old   January 12, 2011, 06:10
Default
  #6
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,665
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
Your expert parameter turns the solving of the volume fraction equation off. You are not going to get far when you are not solving the equations.

I have no idea why pressure is not in the output file.
ghorrocks is offline   Reply With Quote

Old   January 13, 2011, 07:43
Default
  #7
Senior Member
 
Join Date: Mar 2009
Posts: 138
Rep Power: 17
camoesas is on a distinguished road
There is pressure in the out files indeed.
But I have to choose Solver Pressure instead of Pressure. This comes with the cavitation model. Its explained in the User Help
camoesas is offline   Reply With Quote

Old   February 24, 2019, 22:20
Default
  #8
New Member
 
luo dan
Join Date: Sep 2018
Posts: 27
Rep Power: 7
LUO DAN is on a distinguished road
I also encountered this problem. And what is the cause of this problem? I am so confused. I hope I can get your help. Thank you very much!
LUO DAN is offline   Reply With Quote

Old   February 24, 2019, 22:49
Default
  #9
Senior Member
 
Join Date: Jun 2009
Posts: 1,788
Rep Power: 31
Opaque will become famous soon enough
Could you post the message in the output file?

The <unknown> variable is out of bounds. the suggestion will depend on which variable is listed,
Opaque is offline   Reply With Quote

Old   February 25, 2019, 00:03
Default
  #10
New Member
 
luo dan
Join Date: Sep 2018
Posts: 27
Rep Power: 7
LUO DAN is on a distinguished road
the error is as follows:
thank you!

Slave: 9
Slave: 9 Fatal bounds error detected
Slave: 9 ---------------------------
Slave: 9 Variable: Absolute Pressure
Slave: 9 Locale : S1

Parallel run: Received message from slave
-----------------------------------------
Slave partition : 9
Slave routine : ErrAction
Master location : Message Handler
Message label : 001100279
Message follows below - :

+--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine ErrAction. |
| Message: |
| Stopped in routine ENFORCE_BOUNDS |
| |
| |
| |
| |
| |
+--------------------------------------------------------------------+

+--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine MESG_RETRIEVE. |
| Message: |
| Stopping the run due to error(s) reported above |
| |
| |
| |
| |
| |
+--------------------------------------------------------------------+

+--------------------------------------------------------------------+
| An error has occurred in cfx5solve: |
| |
| The ANSYS CFX solver exited with return code 1. No results file |
| has been created. |
+--------------------------------------------------------------------+

End of solution stage.

+--------------------------------------------------------------------+
| The following user files have been saved in the directory |
| D:/LUODAN/may/seal_pending/dp0_CFX12_Solution/CFX12_021: |
| |
| pids, mon |
+--------------------------------------------------------------------+


+--------------------------------------------------------------------+
| For CFX runs launched from Workbench, the final locations of |
| directories and files generated may differ from those shown. |
+--------------------------------------------------------------------+


+--------------------------------------------------------------------+
| Warning! |
| |
| After waiting for 60 seconds, 1 solver manager process(es) appear |
| not to have noticed that this run has ended. You may get errors |
| removing some files if they are still open in the solver manager. |
+--------------------------------------------------------------------+
LUO DAN is offline   Reply With Quote

Old   February 25, 2019, 00:30
Default
  #11
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,665
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
You have a bounds error on the Absolute Pressure. The highest pressure CFX can handle is very high, 1E10Pa I suspect, but the absolute pressure cannot be zero or negative in compressible simulations. So something is causing the absolute pressure to exceed these limits.

Most of the time this is caused by numerical instability and the simulation is diverging. In this case this FAQ is relevant: https://www.cfd-online.com/Wiki/Ansy...do_about_it.3F

In a small number of highly specialised cases the negative absolute pressure is real. These cases cannot be modelled by CFX. But they really only occur in extreme MEMS modelling cases so most people don't come across this (fortunately).
__________________
Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.
ghorrocks is offline   Reply With Quote

Old   February 25, 2019, 01:41
Default
  #12
New Member
 
luo dan
Join Date: Sep 2018
Posts: 27
Rep Power: 7
LUO DAN is on a distinguished road
May multi-core parallel computing cause this Problem? Because the same case i simulated before did not arise such problems.Thank you!
LUO DAN is offline   Reply With Quote

Old   February 25, 2019, 05:44
Default
  #13
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,665
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
It is unusual for multiprocessor to cause this type of error, but not impossible. It still suggests numerical instability, so the FAQ is applicable for that.
__________________
Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.
ghorrocks is offline   Reply With Quote

Old   February 25, 2019, 07:32
Default
  #14
Senior Member
 
Gert-Jan
Join Date: Oct 2012
Location: Europe
Posts: 1,818
Rep Power: 27
Gert-Jan will become famous soon enough
Quote:
Originally Posted by LUO DAN View Post
the error is as follows:
thank you!

Slave: 9
Slave: 9 Fatal bounds error detected
Slave: 9 ---------------------------
Slave: 9 Variable: Absolute Pressure
Slave: 9 Locale : S1

..........


+--------------------------------------------------------------------+
| Warning! |
| |
| After waiting for 60 seconds, 1 solver manager process(es) appear |
| not to have noticed that this run has ended. You may get errors |
| removing some files if they are still open in the solver manager. |
+--------------------------------------------------------------------+



In order to really help you, we need to know what problem your are solving and what settings you used. Please share in text format.
Gert-Jan is offline   Reply With Quote

Old   February 26, 2019, 02:25
Default
  #15
New Member
 
luo dan
Join Date: Sep 2018
Posts: 27
Rep Power: 7
LUO DAN is on a distinguished road
I simulated the carbon dioxide two-phase flow in the seal. The settings are listed in the following text. Thank you!
Attached Files
File Type: txt co2 twophase simulation.txt (8.1 KB, 19 views)
LUO DAN is offline   Reply With Quote

Old   February 26, 2019, 04:40
Default
  #16
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,665
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
You are using a complex and custom material model. They often cause strange errors and are often very hard to converge.

I see you have set a very small timescale factor, which suggests you have already tried lowering the time step to get convergence.

This simulation is too complex to debug on the forum. All I can recommend is the general procedure for getting complex material models to converge:
1) Do a run using simple, built-in material models, maybe single phase ideal gas. Make sure this runs well and stably before proceeding.
2) Then add the complex components one at a time. In your case maybe do a single phase model using your RGP model.
3) Then do a model using multiphase, but simple fluid properties (maybe ideal gas)
4) If all your complex models work OK by themselves then try combining them. Be prepared for all sorts of new and unexpected error messages
__________________
Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.
ghorrocks is offline   Reply With Quote

Old   February 26, 2019, 14:18
Default
  #17
Senior Member
 
Gert-Jan
Join Date: Oct 2012
Location: Europe
Posts: 1,818
Rep Power: 27
Gert-Jan will become famous soon enough
Looks like you are trying to solve a degassing process, with nucleation, while assuming equilibrium conditions. At least I don't see any user defined source terms.

Neverthelss this is a very difficult problem. I fully agree with Glenn. Start as simple as possible and step by step increase complexity by adding physics.

Last edited by Gert-Jan; February 27, 2019 at 04:05.
Gert-Jan is offline   Reply With Quote

Old   February 27, 2019, 01:29
Default
  #18
New Member
 
luo dan
Join Date: Sep 2018
Posts: 27
Rep Power: 7
LUO DAN is on a distinguished road
Yes, I have tried to simulate my case with single-phase RGP and it had a good convergence. I continued to simulate two-phase co2 flow and took the above results as initial conditions. But it is so hard to converge yet at a very small time step. Is this reasonable?
LUO DAN is offline   Reply With Quote

Old   February 27, 2019, 06:42
Default
  #19
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,665
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
If the simulation is unstable then a very small time step will be required. If the simulation is not correctly set up then it will diverge no matter what time step you use.

You are doing a very complex simulation and you should expect it to be difficult to work working. It is also too complex to debug over the forum as it would take an expert many hours to do I suspect, and nobody has that sort of time to give to the forum. You are going to have to work this one out yourself I suspect.
__________________
Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.
ghorrocks is offline   Reply With Quote

Old   April 4, 2022, 08:10
Default Very helpful answers
  #20
New Member
 
No Real Name
Join Date: Sep 2016
Posts: 4
Rep Power: 9
meusha is on a distinguished road
Quote:
Originally Posted by ghorrocks View Post
Your simulation is not converging well. Need to improve the numerical stability - smaller timesteps, better mesh quality and check the physics.



This is all you ever hear on this forum, unfortunately.
meusha is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Stopped in routine ENFORCE_BOUNDS Ram CFX 3 November 13, 2019 23:00
user subroutine error CFDUSER CFX 2 December 9, 2006 07:31
user defined function cfduser CFX 0 April 29, 2006 11:58
CFX 10 User Sub Routine Claudia CFX 6 February 15, 2006 09:32
FORTRAN Routine - variable passing Malcolm CFX 1 August 11, 2005 19:51


All times are GMT -4. The time now is 03:14.