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-   -   isolated fluid regions were found (https://www.cfd-online.com/Forums/cfx/25210-isolated-fluid-regions-were-found.html)

alfin February 9, 2008 17:53

isolated fluid regions were found
 
i am trying to solve two way fluid structure interaction with ansys as inp file

i get the following error message can anybody help me out plzzz i am stuck

-----------------------------------------------------------

If the isolated regions do not have the pressure level set either by the boundary conditions or using a reference pressure equation, you may encounter severe robustness problems.

This situation may have arisen because a domain interface was not properly defined during problem setup. Please carefully check the setup.

The solver will stop now and write a results file. The isolated regions can be visualised in CFX Post by making plots of the variable "Isolated Volumes".

If you are sure that the pressure level is set in each isolated fluid region then you can force the solver to turn off this check by setting the expert parameter "check isolated regions = f".

+--------------------------------------------------------------------+ | An error has occurred in cfx5solve: | | | | The ANSYS CFX solver exited with return code 1. | +--------------------------------------------------------------------+

End of solution stage.

+--------------------------------------------------------------------+ | An error has occurred in cfx5solve: | | | | ANSYS Solver terminated with return code 3840 | +--------------------------------------------------------------------+


CycLone February 11, 2008 13:01

Re: isolated fluid regions were found
 
This is indicating that their are multiple regions in your model which are not connected. If this is your intent, just set the expert parameter as suggested. If not, check your model to see whether you are missing something or need to add an interface somewhere.

I think the solver also writes out a res.err file which you can load into Post and will include a variable you can plot (or create an isovolume on) to find the isolated regions.

-CycLone

flyingd July 31, 2009 23:14

check isolated fluid region
 
Quote:

Originally Posted by alfin
;85979
i am trying to solve two way fluid structure interaction with ansys as inp file

i get the following error message can anybody help me out plzzz i am stuck

-----------------------------------------------------------

If the isolated regions do not have the pressure level set either by the boundary conditions or using a reference pressure equation, you may encounter severe robustness problems.

This situation may have arisen because a domain interface was not properly defined during problem setup. Please carefully check the setup.

The solver will stop now and write a results file. The isolated regions can be visualised in CFX Post by making plots of the variable "Isolated Volumes".

If you are sure that the pressure level is set in each isolated fluid region then you can force the solver to turn off this check by setting the expert parameter "check isolated regions = f".

+--------------------------------------------------------------------+ | An error has occurred in cfx5solve: | | | | The ANSYS CFX solver exited with return code 1. | +--------------------------------------------------------------------+

End of solution stage.

+--------------------------------------------------------------------+ | An error has occurred in cfx5solve: | | | | ANSYS Solver terminated with return code 3840 | +--------------------------------------------------------------------+

Hello! Will you please tell detail. Where set up the pressure level.
Where set up solving to turn off check?
thinks!

flyingd July 31, 2009 23:17

Hello! Will you please tell detail. Where set up the pressure level.
Where set up solving to turn off check?
thinks!

flyingd July 31, 2009 23:43

asking for pressure level
 
in pressure level setting, what the value of reference pressure should be?
reference air pressure or hydra static pressure, or it is hydra static pressure, I am not sure.
At the same time where we can turn off the check by setting the export parameter?
I will you or every one help me.
Thinks a lot.
Meantime, think alfin's help.

flyingd August 1, 2009 03:40

asking for help
 
Quote:

Originally Posted by CycLone
;86002
This is indicating that their are multiple regions in your model which are not connected. If this is your intent, just set the expert parameter as suggested. If not, check your model to see whether you are missing something or need to add an interface somewhere.

I think the solver also writes out a res.err file which you can load into Post and will include a variable you can plot (or create an isovolume on) to find the isolated regions.

-CycLone

but , my model is in no free surface, there is no problem.
If I set the parameter of fress surface, it check no isolated fluid region.
At the same time,I have set the pressure level.
The reference pressure is relative air pressue? location(0,0,0).
Right?

mauricio August 3, 2009 02:01

Hi, I believe usually "Isolated fluid regions" Message has to do with problems in the geometry/ mesh, i think. what are your domains? are there any meshes that are "On top of each other" ? like alfin said, it could so be regions that are not connected; and as the solver says, you can view this regions in the cfx-post; try to open the ...resulting file from your failed run in cfx-post and get plot of these regions. It should give you a hint of where you have to work at. The last option is to disable isolated region checking in the solver; I'm not sure if you'll want that, but you can do that by adding a expert parameter.

malrawi February 10, 2010 16:20

Quote:

Originally Posted by alfin
;85979
i am trying to solve two way fluid structure interaction with ansys as inp file

i get the following error message can anybody help me out plzzz i am stuck

-----------------------------------------------------------

If the isolated regions do not have the pressure level set either by the boundary conditions or using a reference pressure equation, you may encounter severe robustness problems.

This situation may have arisen because a domain interface was not properly defined during problem setup. Please carefully check the setup.

The solver will stop now and write a results file. The isolated regions can be visualised in CFX Post by making plots of the variable "Isolated Volumes".

If you are sure that the pressure level is set in each isolated fluid region then you can force the solver to turn off this check by setting the expert parameter "check isolated regions = f".

+--------------------------------------------------------------------+ | An error has occurred in cfx5solve: | | | | The ANSYS CFX solver exited with return code 1. | +--------------------------------------------------------------------+

End of solution stage.

+--------------------------------------------------------------------+ | An error has occurred in cfx5solve: | | | | ANSYS Solver terminated with return code 3840 | +--------------------------------------------------------------------+

Hi alfin,

Please did you solve the problem as I have the same ones, please late me know what you did for it, cheers

rushabh October 11, 2011 20:38

Quote:

Originally Posted by CycLone
;86002
I think the solver also writes out a res.err file which you can load into Post and will include a variable you can plot (or create an isovolume on) to find the isolated regions.

-CycLone

Could you elaborate on plotting (or creating an isovolume)? I would really appreciate the help since that's exactly what I need right now.

ghorrocks October 12, 2011 06:45

This is simple post processing, have a look in the tutorials.

marlon September 9, 2015 08:13

Well, I believe this error occurs when there are more than one fluid path in the design and we create a simple boundary grouping all of them.

For example: instead of create one "inlet" selecting all the inlet regions, try to separate the inlets in different inlet boundaries and separete the fluid in different fluid domains.

ghorrocks September 9, 2015 19:08

The error message is quite clear - it is because there regions of mesh which are not connected. This does also mean the boundary conditions are not connected but the error is not due to whether the boundaries are grouped or not. The problem is more fundamental then that.

cfdesf1990 October 5, 2015 07:25

isolated regions
 
Hello buddies
I am new in CFX and ICEM. I am trying to simulate a submarine near free-surface with a surface wave. Therefore, I have to use structured mesh near the free surface both up and below. I also use structured mesh in the rest of domain. So I have a domain with 4 regions( water domain with unstructured, water domain near free surface with struchtured mesh, air domain near surface with structured mesh, and air domain on top of domain with unstructured mesh). I used ICEM and unstructured mesh for those 2 volumes and blocking strategy for structured mesh for 2 volumes near the free surface. I used merge option as well but when I want to simulate it in CFX the error " 4 isolated regions" appears. Is it true that I disable expert mesh in setting or not?
Do u have any other suggestion?

I really appreciate your help.

ghorrocks October 5, 2015 17:51

No. The error message means your regions are not connected. Check the interfaces/mesh which connect these regions. Do not disable the expert setting.

cfdesf1990 October 8, 2015 01:36

Thanks dear ghorrocks for your response. I found out that I must define some interfaces between regions.


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