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-   -   Problem with icoFsiFoam in the latest OFdev (http://www.cfd-online.com/Forums/openfoam-bugs/62306-problem-icofsifoam-latest-ofdev.html)

mathieu February 17, 2009 22:24

Hi people ! I used to run 2
 
Hi people !

I used to run 2D fluid-structure interaction simulation with "closed" fluid-solid interface (see case A in the attachment). My current installation is OpenFOAM 1.4.1-dev revision 784.

Now, if I update my OpenFOAM installation to the latest 1.4.1-dev or even to the latest 1.5-dev version, those kind of simulation don't work anymore. However, if the fluid-solid interface is "open" (see case B in the attachment), then there is no problem at all (in all version).

The following package contains both cases A and B that can be run with the standard icoFsiFoam solver. More details are also provided in a pdf file.

Any help would be appreciated ! Kind regards,

Mathieu



mathieu February 17, 2009 22:29

http://www.cfd-online.com/Ope
 
http://www.cfd-online.com/OpenFOAM_D...hment_icon.gif package.tgz

hjasak February 18, 2009 07:47

Sorry, I do not get it. I hav
 
Sorry, I do not get it. I have just run caseA and I can see forces being transferred, a flow field, a structural deformation field and a moving mesh for both the fluid and the solid.

When you say "it does not work any more", what precisely does not work:
- the case does not run
- you get a floating point exception
- you do not get the flow field
- you do not get structural deformation
- you do not get mesh motion
- force transfer is not correct

I am missing something, but don't know what...

More info please,

Hrv

hjasak February 18, 2009 08:36

Got it: this is to do with a s
 
Got it: this is to do with a search algorithm for a multiply projected boundary (thank Gavin and his FSI artery simulation).

Whta happens is that for a closed surface with escapes, you cannot guarantee the projection will be correct using the fast algorithm. I have changed the switch in

~/OpenFOAM/OpenFOAM-1.5-dev/etc/controlDict

to use

nSquaredProjection 1;

in the OptimisationSwitches section and all works well. The deformation on the solut surface looks a bit stupid (you may want to use mesh motion to deform that side as well), but at least we know what the problem (and solution) are.

Enjoy,

Hrv

mathieu February 18, 2009 13:12

Dear Hrv, Thanks for the re
 
Dear Hrv,

Thanks for the reply ! I changed nSquaredProjection to 1 and the problem seems to be gone. Thanks again,

Mathieu

mathieu February 19, 2009 14:16

Dear Hrv, I investigated th
 
Dear Hrv,

I investigated this issue further and I found that there is still a problem with the mesh when using OF-1.5-dev with nSquaredProjection set to 1 (no more problems in the latest revision of 1.4.1-dev though!). See the right tip of the plate in the following pictures.

1.4.1-dev:
http://www.cfd-online.com/OpenFOAM_D.../126/11305.jpg

1.5-dev:
http://www.cfd-online.com/OpenFOAM_D.../126/11306.jpg

Is there something else I am missing or is this a bug ?

By the way, what did you mean by "solut surface" in your last message ?

Regards,

Mathieu

hjasak February 19, 2009 14:37

This is the kind of work I do
 
This is the kind of work I do under a support contract. Alternatively, you have a dig through the code yourself.

Hrv

maruthamuthu_venkatraman September 23, 2010 08:22

Quote:

Originally Posted by mathieu (Post 207822)
Dear Hrv,

I investigated this issue further and I found that there is still a problem with the mesh when using OF-1.5-dev with nSquaredProjection set to 1 (no more problems in the latest revision of 1.4.1-dev though!). See the right tip of the plate in the following pictures.

1.4.1-dev:
http://www.cfd-online.com/OpenFOAM_D.../126/11305.jpg

1.5-dev:
http://www.cfd-online.com/OpenFOAM_D.../126/11306.jpg

Is there something else I am missing or is this a bug ?

By the way, what did you mean by "solut surface" in your last message ?

Regards,

Mathieu


Hello Mathiew,
Have you fixed the error in 1.5-dev version for icoFSIFoam solver. As u stated 1.4-dev vrsion has no problems, Do I lack something if i use that version.

Regards
Muthu


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