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

engine simulation with mesh motion and topological changes

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

Like Tree3Likes

Reply
 
LinkBack Thread Tools Display Modes
Old   May 31, 2011, 05:43
Default
  #101
Senior Member
 
Vangelis Skaperdas
Join Date: Mar 2009
Location: Thessaloniki, Greece
Posts: 163
Rep Power: 9
vangelis is on a distinguished road
Hi there,

The "Output Sets" option was introduced
in ANSA v13.1.2, so if you have an earlier
version you will not see it.

I would recommend that you get the latest
one which is v13.1.3.

If you also want internal faces, you can indeed
create them with VOL-SHELL and then assign
them to a PID of type INTERNAL (you can do this
if you edit the PID card).

These elements will then be output in the faceZones
file. I believe you can then change this into a SET
using openfoam utility tools.

Best regards

Vangelis
vangelis is offline   Reply With Quote

Old   May 31, 2011, 06:33
Default
  #102
Member
 
Join Date: Nov 2010
Posts: 86
Rep Power: 6
abminternet is on a distinguished road
Great thanks, you were right, I was using the wrong version now it works like a charm, it even writes the sets itself, no need to do zones to sets
abminternet is offline   Reply With Quote

Old   May 31, 2011, 07:02
Default
  #103
Senior Member
 
Vangelis Skaperdas
Join Date: Mar 2009
Location: Thessaloniki, Greece
Posts: 163
Rep Power: 9
vangelis is on a distinguished road
you are welcome
vangelis is offline   Reply With Quote

Old   May 31, 2011, 18:19
Default
  #104
Member
 
Join Date: Nov 2010
Posts: 86
Rep Power: 6
abminternet is on a distinguished road
Hey guys, so now that i can do sets, (thanks again vangelis ) it turns out I may be doing them wrong. The piston does not move, the cells that are supposed to move with the valve just get streched (only the points in contact with the valve top move), and the cells that are supposed to move and layered do nothing :S. So maybe I got it wrong. The pistonAuxPoints are the points that are supposed to move right? So that would be for example all 8 points of each cell in direct contact with the piston??
also, what is the cylinderSet, is it every other cell in the cylinder that does not contain those points? (that would mean the layer of cells just above the piston cells are not in the cylinderSet either?

and for the valves, staticPoints are the points belonging to the tetra cells above the hexas? and the movingInternalPoints, are they the points belonging to the hexa cells for layering? and the
movingPoints are then the lower tetra cells, the ones that move together with the valve?, and also the staticCells and movingCells, they correspond to the staticPoints and movingPoints i guess.

sorry that i ask so many questions, i just feel i am so close to making it work. Any help would be greatly appreciated

kind regards
abminternet is offline   Reply With Quote

Old   June 1, 2011, 08:33
Default
  #105
Member
 
Join Date: Nov 2010
Posts: 86
Rep Power: 6
abminternet is on a distinguished road
hi everyone, so, after reading the code carefully, I have one question. Is the code even complete? It seems like it is not :S
abminternet is offline   Reply With Quote

Old   June 9, 2011, 09:00
Default
  #106
Senior Member
 
Join Date: Oct 2009
Posts: 136
Rep Power: 7
Peter_600 is on a distinguished road
Hi,

sorry I am a little bit busy at the moment. I ll come back to u the days with a small instruciton for the accordionEngineMesh class.
Could you post a figure of ur grid ?

thx
Peter
Peter_600 is offline   Reply With Quote

Old   June 10, 2011, 05:29
Default Hi Peter
  #107
Member
 
Join Date: Nov 2010
Posts: 86
Rep Power: 6
abminternet is on a distinguished road
No problem. My mesh looks like the picture. It is a simplified 2D mesh of my 3D case. I am using it for testing. The valve is not really tilted, but it is just a test, so I guess it should work just the same way, cause the axis and direction of the valve are specified. Well good luck with all the work, I guess I'll hear from you when you are a bit more relaxed.
abminternet is offline   Reply With Quote

Old   June 10, 2011, 05:30
Default
  #108
Member
 
Join Date: Nov 2010
Posts: 86
Rep Power: 6
abminternet is on a distinguished road
forgot the pic, here it is
Attached Images
File Type: jpg valve2D.jpg (59.3 KB, 151 views)
abminternet is offline   Reply With Quote

Old   August 17, 2011, 10:58
Default
  #109
New Member
 
Danil
Join Date: Aug 2011
Posts: 1
Rep Power: 0
_DF_ is on a distinguished road
Hi,

Is there sonicTurbDyMEngineFoam solver for OpenFOAM 2.0.1?
_DF_ is offline   Reply With Quote

Old   November 29, 2011, 12:11
Default
  #110
New Member
 
Fabien DOS SANTOS
Join Date: Oct 2009
Location: Nevers, FRANCE
Posts: 8
Rep Power: 7
Paebin is on a distinguished road
Hello everybody,

I have downloaded the simpleEngine case and it works great. It is a good example to understand the preparation of a dynamic mesh case in openFoam.

But in fact I'm more interested by the flow inside an injector than in a whole combustion chamber. I would like to move the injector needle, so I have to use a dynamic mesh. I don't need engineTime, I have no piston and my valve does not have a bottom, but my case is really similar to an engine valve (need sliding, layering and attach/detach). For that, and to start, I used the original linearValveLayersFvMesh class. But The attach/detach feature is not included in this class, so I have mixed linearValveLayersFvMesh and simpleEngineTopoFvMesh in order to add it.

I have tested my mesh with moveDynamicMesh and it works great. But with the interDyFoam multiphase solver, I have a problem with attach/detach, I got a "Floating point exception" during the first time step in both RANS (K-epsilon) and LES (oneEqEddy). If I switch off the turbulence in RANS or use laminar with attach/Detach, it works. If I use turbulence (RANS or LES) without attach/Detach (by removing all the faces in the "detachFaces" dict), it works too. I'm using 1.6-ext (updated last week).

My problem seems really similar to the one in the beginning of this thread but the simpleEngineStem case works on my computer, so the problem should be solved. Did anyone try to use attach/Detach with interDyFoam ?

Regards,
Fabien.
Paebin is offline   Reply With Quote

Old   January 12, 2012, 00:38
Default Seqmentation fault in engineTopoChangerMesh layerAR
  #111
Member
 
Abhishek
Join Date: Dec 2010
Posts: 38
Rep Power: 6
Abhishekd18 is on a distinguished road
Hi,

I am trying to run dieselEngineFoam_Scania case with layering. I have done the necessary changes in dieselEngineFoam solver and created dieselEngineDyMFoam solver. But I am getting segmentation fault in first time step. It seems that the solver enters mesh.update() and doesn't come out which is causing segmentation fault. Can anyone help on this problem?

My mesh is not the sector mesh. I have extruded it 360 deg full so I don't have cyclic boundaries.
Abhishekd18 is offline   Reply With Quote

Old   January 27, 2012, 22:31
Default HCCI geometry
  #112
New Member
 
majid
Join Date: May 2011
Posts: 3
Rep Power: 6
kaparzo-shb is on a distinguished road
Hi, every one,
please i need a engine 3d chamber gemetry for running un test of my film model. am working with Gambit and fluent.

Thanks.
kaparzo-shb is offline   Reply With Quote

Old   February 10, 2012, 05:57
Default dieselEngineFoam solver crashes in parallel at the start of injection
  #113
Member
 
Abhishek
Join Date: Dec 2010
Posts: 38
Rep Power: 6
Abhishekd18 is on a distinguished road
Hi,

I am running dieselEngineFoam in parallel on 4 processors. But as the spray injection starts the solver crashes. The setup runs perfectly fine in serial. I am using OpenFoam 1.6 ext. Can anyone help me on this?

Thanks.

Last edited by Abhishekd18; February 15, 2012 at 08:12.
Abhishekd18 is offline   Reply With Quote

Old   February 15, 2012, 08:10
Default
  #114
Member
 
Abhishek
Join Date: Dec 2010
Posts: 38
Rep Power: 6
Abhishekd18 is on a distinguished road
Hi, everyone,

Does anyone know how openFoam maps fields while using layer Addition? I am using openfoam 1.6-ext dieselEngineFoam. The solver crashes (Floating point exception) when layer addition starts. Velocity magnitude is very high 7783 m/s and courant no. is also high. I think it is related to mapping fields after adding the layer.

Please reply if anyone knows anything about this.

Thanks.
Abhishekd18 is offline   Reply With Quote

Old   February 15, 2012, 09:44
Default
  #115
Senior Member
 
Sandeep Menon
Join Date: Mar 2009
Location: Amherst, MA
Posts: 386
Rep Power: 15
deepsterblue will become famous soon enough
Mapping fields for layer addition is meant to be relatively straightforward - All cells in the new layer are inflated from zero-volume.

Are you using adaptive time-stepping?
__________________
Sandeep Menon
University of Massachusetts Amherst
https://github.com/smenon
deepsterblue is offline   Reply With Quote

Old   February 15, 2012, 11:29
Default
  #116
Member
 
Abhishek
Join Date: Dec 2010
Posts: 38
Rep Power: 6
Abhishekd18 is on a distinguished road
Yes. I am using adjustable Time Step. I am limiting max courant number to 0.1. But after layer addition it shows maxCo = 1.8 something.
Abhishekd18 is offline   Reply With Quote

Old   February 15, 2012, 11:35
Default
  #117
Senior Member
 
Sandeep Menon
Join Date: Mar 2009
Location: Amherst, MA
Posts: 386
Rep Power: 15
deepsterblue will become famous soon enough
You might want to manually print out the velocity field in the newly created cells (and face-fluxes phi for newly created faces) after the mesh-update to ensure that it looks reasonable.

Is this in parallel? If so, you might have to ensure that the partitioning is perpendicular to the motion-axis, since layer-addition / removal is known to be finicky there..
__________________
Sandeep Menon
University of Massachusetts Amherst
https://github.com/smenon
deepsterblue is offline   Reply With Quote

Old   February 15, 2012, 12:01
Default
  #118
Member
 
Abhishek
Join Date: Dec 2010
Posts: 38
Rep Power: 6
Abhishekd18 is on a distinguished road
I have done manual decomposition which takes care of the direction of motion of piston, cyclic boundaries and layering. In fact, it runs perfectly fine when piston moves from BDC to TDC. The problem starts during expansion stroke when layering starts.

But the solution crashes after layer is added. I don't have even single time step after layer addition so that I can plot the velocity field.
Abhishekd18 is offline   Reply With Quote

Old   February 15, 2012, 12:05
Default
  #119
Senior Member
 
Sandeep Menon
Join Date: Mar 2009
Location: Amherst, MA
Posts: 386
Rep Power: 15
deepsterblue will become famous soon enough
That's because your runTime.write() is after your solution loop. Place it after the mesh.update() call, and you'll get the mapped field written out to disk.

You'll have to roll-up your sleeves and write some code for this.
__________________
Sandeep Menon
University of Massachusetts Amherst
https://github.com/smenon
deepsterblue is offline   Reply With Quote

Old   February 15, 2012, 12:18
Default
  #120
Member
 
Abhishek
Join Date: Dec 2010
Posts: 38
Rep Power: 6
Abhishekd18 is on a distinguished road
Ok. I will do that.

What should I do after that?

What kind of code do I have to write?

And few more questions
1. When I modified dieselEngineFoam for layering, I did it as it is done in sonicTurbDyMFoam. But the solution diverges when layering starts. When I commented the statement "# include compressibleCorrectPhi.H" it runs perfectly fine. As far as I understood, compressibleCorrectPhi.H solves pressure correction after mesh change and it should be included.

2. While running in parallel, the solution crashed at the start of injection. When I started debugging the code, it turned out to be some problem with the statement "# include findInjectorCell.H" in sprayInject.C. Again on commenting the line, the solver runs and I can see the spary injected from the desired location.

What could be the reasons?
Abhishekd18 is offline   Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


LinkBacks (?)
LinkBack to this Thread: http://www.cfd-online.com/Forums/openfoam/83177-engine-simulation-mesh-motion-topological-changes.html
Posted By For Type Date
Untitled document This thread Refback February 4, 2014 12:36

Similar Threads
Thread Thread Starter Forum Replies Last Post
Dynamic moving mesh Pei-Ying Hsieh (Hsieh) OpenFOAM Running, Solving & CFD 64 June 7, 2012 10:04
engine simulation with mesh motion and topological changes abminternet OpenFOAM 0 December 16, 2010 12:47
Good mesh for pistoncylinder application Serkan Cetin OpenFOAM Other Meshers: ICEM, Star, Ansys, Pointwise, GridPro, Ansa, ... 4 November 3, 2010 08:36
Radiation and miscellaneous enhancements vtk_fan OpenFOAM Running, Solving & CFD 6 February 18, 2008 00:49
Valve action Hrvoje Jasak (Hjasak) OpenFOAM Running, Solving & CFD 0 January 13, 2005 14:23


All times are GMT -4. The time now is 06:02.