CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Community Contributions

[ImmersedBoundary] Immersed Boundary Method in OpenFOAM-3.1-ext

Register Blogs Community New Posts Updated Threads Search

Like Tree29Likes

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 30, 2015, 00:56
Default
  #41
Member
 
Ali
Join Date: Oct 2013
Location: St John's Canada
Posts: 31
Rep Power: 13
ashim is on a distinguished road
Dear Prof Hrvoje Jasak,

Thank you very much for your reply. In foam extend-3.2, the cylBumpInterIbFoam tutorial runs without any problem. But if I refine the ibCylinder for level 3 using refineImmersedBoundaryMesh -ibCellCellFaces the solver show all.points < 5: 2 , If I use level 4 refinement it end up with singular matrix error, If I refine ibCylinder region using mesh refinement options the courant number diverges after 0.10 sec. I am wondering about refinement technique which can be used for immersed body. Actually I want use immersed boundary method (as overset is not available in public release) for dynamic body simulation in waves.

Best Regards,

Ali
ashim is offline   Reply With Quote

Old   October 8, 2015, 04:18
Default Rotating ImmersedBoundaries
  #42
New Member
 
Robert Grandl
Join Date: Aug 2015
Posts: 16
Rep Power: 11
RobertG is on a distinguished road
Hy,
I'm trying to make the ImmersedBoundaries move.
I already had a look in to the source code.
Unfortunately, I did not understand it realy good.
Can someone tell me, which file or where I can find the code, which is resposible to read the .stl-files.

It whould be realy nice, if some one can give me a short overview ouver the programm structures of immersed boundaries.

Best regards
RobertG.
RobertG is offline   Reply With Quote

Old   October 8, 2015, 06:41
Default
  #43
Member
 
Join Date: May 2014
Posts: 40
Rep Power: 12
Phil_ is on a distinguished road
Hi Robert,

I looked into this too but couldn't find a proper solution yet.

If you "just" want to move the IB but not alter the body-shape you can take a look at the movePoints() / moveTriSurfacePoints() method in immersedBoundaryPolyPatch.C. It should be possible to move the already existing IB-points. (I think this happens via dynamicMesh handling.)

If you want to alter the IB-body-shape altogether it's getting complicated. I have not been able to read in a new .stl/.ftr during runtime. If someone has a clue how to do that, please respond

Best regards,
Philip

Last edited by Phil_; October 8, 2015 at 08:26.
Phil_ is offline   Reply With Quote

Old   October 8, 2015, 07:54
Default
  #44
Senior Member
 
Hrvoje Jasak
Join Date: Mar 2009
Location: London, England
Posts: 1,907
Rep Power: 33
hjasak will become famous soon enough
Have a look in 3.2 nextRelease branch: I made a dynamic mesh class and a tutorial for a moving immersed boundary.

Enou
philippose, utkunun, Phil_ and 1 others like this.
__________________
Hrvoje Jasak
Providing commercial FOAM/OpenFOAM and CFD Consulting: http://wikki.co.uk
hjasak is offline   Reply With Quote

Old   October 8, 2015, 11:01
Default
  #45
New Member
 
Robert Grandl
Join Date: Aug 2015
Posts: 16
Rep Power: 11
RobertG is on a distinguished road
Hello Philip and Prof. Hrvoje Jasak,
thanks a lot for your fast replay.
I want to simulate an twin screw extruder.
Therefore, I have two rotating parts.
But I want to couple the CFD-Simulation with an DEM-Simulation, using foam-extendet, LIGGGHTS and CFDEM.
So, I have to create my own solver, based on the cfdemSolverPisoScalar.

Is it possible?

Best regards
RobertG.
RobertG is offline   Reply With Quote

Old   October 8, 2015, 11:18
Default
  #46
Senior Member
 
Hrvoje Jasak
Join Date: Mar 2009
Location: London, England
Posts: 1,907
Rep Power: 33
hjasak will become famous soon enough
I don't think you can do a screw extruder with immersed boundary. Tolerances in the gap are just too fine and the flow is critically dependent on the resolution in gaps.

At Wikki we have done projects with screw equipment using custom mesh motion. This is probably some of the most beautiful and challenging moving mesh cases I have seen or done Not easy, though.

Doing this through Wikki would require funding and an industrial partner; you are most welcome to try IBM or alternative dynamic mesh, but be advised: this is not easy!

Hrv
__________________
Hrvoje Jasak
Providing commercial FOAM/OpenFOAM and CFD Consulting: http://wikki.co.uk
hjasak is offline   Reply With Quote

Old   October 8, 2015, 12:31
Default
  #47
New Member
 
Robert Grandl
Join Date: Aug 2015
Posts: 16
Rep Power: 11
RobertG is on a distinguished road
Hello Prof. Hrvoje Jasak,
I'm sorry, I used, the term twin screw extruder, because, it is more common.
In fakt it is more than a co-rotating twin screw mixing reactor.
The rotation-zylinder of both screw are overlapping, which is the reason, why I can't use the dynamic meshing.
But, between the two screw is always enough space.
Thanks a lot for your help.

Best regards
RobertG
RobertG is offline   Reply With Quote

Old   October 8, 2015, 14:24
Default
  #48
New Member
 
Daniel Brunner
Join Date: Sep 2015
Posts: 8
Rep Power: 11
DaniB1989 is on a distinguished road
Dear Prof. Hrvoje Jasak

I am trying the analyze the vortex formation / stability etc. at a flapping / heaving fin. Therefore the I'd like to use the immersed boundary method.

As you mentioned you've made a dynamic mesh class and a tutorial for the immersed boundary method. Unfortunately we cannot find it. All of the tutorials of the immersed boundary of the version 3.2 extended (http://sourceforge.net/p/openfoam-ex.../ci/v3.2/tree/) are static.

Are we missing something?

Thanks for the help
Daniel
utkunun likes this.
DaniB1989 is offline   Reply With Quote

Old   October 8, 2015, 14:49
Default
  #49
New Member
 
Robert Grandl
Join Date: Aug 2015
Posts: 16
Rep Power: 11
RobertG is on a distinguished road
Dear Prof. Hrvoje Jasak,
just now, i tried to download the newes version fe32.
When I open the Link at the browser, I see, that there are tutorials for IB.
However there are missing, when I download fe32 via the given git command/url.
But using the "Download Snapshot"-Button works fine ?!

Thanks a lot for the support and your work.

Best regards
RobertG
RobertG is offline   Reply With Quote

Old   October 8, 2015, 19:47
Default
  #50
Retired Super Moderator
 
Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
Posts: 10,982
Blog Entries: 45
Rep Power: 128
wyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to all
Quoting myself from a few minutes ago:
Quote:
Originally Posted by wyldckat View Post
Actually, he was referring to his own repository: http://sourceforge.net/u/hjasak/foam...tRelease/tree/

If you want to start with a new clean copy, you can get it with the following commands:
Code:
git clone git://git.code.sf.net/u/hjasak/foam-extend-3.2 foam-extend-3.2
cd foam-extend-3.2
git checkout nextRelease
If you want to use your already existing repository of foam-extend 3.2, then use these commands:
Code:
foam
git remote add hjasak git://git.code.sf.net/u/hjasak/foam-extend-3.2 
git fetch hjasak
git merge hjasak/nextRelease
The tutorial folder is this one:
Code:
tutorials/immersedBoundary/movingCylinderInChannelIco
The new solver is this one:
Code:
applications/solvers/immersedBoundary/icoDyMIbFoam
wyldckat is offline   Reply With Quote

Old   October 9, 2015, 04:13
Default
  #51
Member
 
Join Date: May 2014
Posts: 40
Rep Power: 12
Phil_ is on a distinguished road
Dear Prof. Hrvoje Jasak,

is it already possible to vary the geometry of the immersed body over time? In the tutorial case the cylinder moves but there's no change in shape.

Best regards
Philip
Nig̣ likes this.
Phil_ is offline   Reply With Quote

Old   October 9, 2015, 10:31
Default
  #52
New Member
 
Daniel Brunner
Join Date: Sep 2015
Posts: 8
Rep Power: 11
DaniB1989 is on a distinguished road
Bruno

Thank you very much for the link. However something is wrong with the dynamic mesh file.
In my case it contains just a "+" at the top and the next ca. 850 lines are empty, which makes no sense to me. The same thing holds true if I try to download it directly by your posted link.

Thanks
Daniel
DaniB1989 is offline   Reply With Quote

Old   October 10, 2015, 06:49
Default
  #53
Retired Super Moderator
 
Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
Posts: 10,982
Blog Entries: 45
Rep Power: 128
wyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to all
I've tested it now. There are a few glitches in his repository. For the fixes, see post #11 in this thread: http://www.cfd-online.com/Forums/ope...tml#post567429

edit: For questions and issues about the Dynamic Meshing with Immersed Boundary Method, please use the dedicated thread: http://www.cfd-online.com/Forums/ope...hannelico.html

Last edited by wyldckat; November 7, 2015 at 13:47. Reason: see "edit:"
wyldckat is offline   Reply With Quote

Old   January 21, 2016, 05:24
Default Potential Flow
  #54
Member
 
Join Date: May 2014
Posts: 40
Rep Power: 12
Phil_ is on a distinguished road
Dear all,

has anyone noticed the potentialIbFoam not working as expected?

Please see the attached pic showing the streamlines of the potential solution
for a pitzDaily.

Is this known? Is there already a fix available? Or am I doing something wrong?

Best regards,
Philip
Attached Images
File Type: png potFlow.png (81.5 KB, 95 views)
Phil_ is offline   Reply With Quote

Old   January 21, 2016, 05:39
Default Potential Flow
  #55
Member
 
Join Date: May 2014
Posts: 40
Rep Power: 12
Phil_ is on a distinguished road
The mentioned behaviour can be noticed in turbulent cases, e.g.

tutorials/immersedBoundary/backwardStepShortTurbulentSimpleIbFoam
tutorials/immersedBoundary/pitzDailyTurbulentSimpleIbFoam
Phil_ is offline   Reply With Quote

Old   January 21, 2016, 08:06
Default
  #56
New Member
 
Robert Grandl
Join Date: Aug 2015
Posts: 16
Rep Power: 11
RobertG is on a distinguished road
Quote:
Originally Posted by singhfme View Post
Has foam-extend-3.2 been released?
jup.
https://openfoamwiki.net/index.php/I...oam-extend-3.2
RobertG is offline   Reply With Quote

Old   January 29, 2016, 03:39
Default Turbulent IBM behaviour
  #57
Member
 
Join Date: May 2014
Posts: 40
Rep Power: 12
Phil_ is on a distinguished road
Dear all,

for a fully developed 2D channel flow at Re=25.000 calculated with k-epsilon turbulence model I get quite different results with simpleIbFoam compared to simpleFoam.

Can anyone confirm this?

Best regards,
Philip
Phil_ is offline   Reply With Quote

Old   February 2, 2016, 09:32
Default
  #58
New Member
 
Robert Grandl
Join Date: Aug 2015
Posts: 16
Rep Power: 11
RobertG is on a distinguished road
Hello,
I have created a new solver, which uses ImmersedBoundarys which are provided at foamExtend 3.2 .
Unfortunately, I don't need the ImmersedBoundarys at all boundary condition.
In dead, it causes at one point an Error in combination with an volScalarField boundary Condition.
Is ist possible to swicht of the ImmersedBoundarys, at boundary condition at which Ib are not neccesery for a correct calculation?

Thanks a lot.

Best regards
RobertG
RobertG is offline   Reply With Quote

Old   March 4, 2016, 09:52
Default
  #59
New Member
 
Join Date: Oct 2013
Posts: 12
Rep Power: 13
Nig̣ is on a distinguished road
Hi foamers,
I'm trying to validate the new Immersed Boundary solvers in the foam extended version 3.2.
For the first case I've tryed the classic 2D cylinder at Reynolds =100.
The body fitted simulation work fine, but with the IB I get some strange results.

In fact the viscous Lift have a mean different to zero (see the attachments), but looking at the averaged time fields the wake is still simmetric to the cylinder axis, so I think that some mistakes are presents in the force calculation functionObject.

Is someone experienced the same problems ??
Have you any guess to how correct the problem ?

Thank you in advance, Nigo
Attached Images
File Type: jpg U_mean.jpg (29.4 KB, 98 views)
File Type: png custom0002.png (4.4 KB, 71 views)
Nig̣ is offline   Reply With Quote

Old   March 4, 2016, 11:00
Default
  #60
Senior Member
 
Hrvoje Jasak
Join Date: Mar 2009
Location: London, England
Posts: 1,907
Rep Power: 33
hjasak will become famous soon enough
We have published laminar and turbulent flow validation results at ERCOFTAC last year and did a validation study on a moving immersed boundary this December.

Why don't you start from those cases and find out where you made q mistake. All validation cases are public
__________________
Hrvoje Jasak
Providing commercial FOAM/OpenFOAM and CFD Consulting: http://wikki.co.uk
hjasak is offline   Reply With Quote

Reply

Tags
immersed boundary method, openfoam-1.6-ext, openfoam-3.1-ext


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
sliding mesh problem in CFX Saima CFX 46 September 11, 2021 08:38
Radiation in semi-transparent media with surface-to-surface model? mpeppels CFX 11 August 22, 2019 08:30
implementation of the Immersed Boundary Method mi_cfd Main CFD Forum 19 April 24, 2019 02:24
Wrong flow in ratating domain problem Sanyo CFX 17 August 15, 2015 07:20
[ImmersedBoundary] who has the paper about immersed boundary method in openfoam blueshit OpenFOAM Community Contributions 1 November 18, 2013 08:16


All times are GMT -4. The time now is 04:28.