CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Meshing & Mesh Conversion

[snappyHexMesh] 3D snappyHexMesh Help

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

Like Tree2Likes
  • 2 Post By lovecraft22

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 20, 2012, 16:43
Default 3D snappyHexMesh Help
  #1
New Member
 
Isaac S
Join Date: Jun 2012
Posts: 6
Rep Power: 13
Ice_Man is on a distinguished road
Hello,

I am attempting to modify the wingMotion tutorial to make it 3D and also change the geometry of the wing.obj. I have been succesful in changing the obj file to what I want and using snappyhexmesh to "snap" that geometry into my blockMesh domain. However, when I run extrudemesh createpatch and simplefoam my object is no longer visible and the geometry becomes two dimensional. I do not know what solvers to run in this situation that will find solutions in 3D.

Any help/guidance is appreciated. I have attached my obj and blockMeshDict.
Thanks,
Isaac
Attached Files
File Type: txt blockMeshDict.txt (1.7 KB, 10 views)
File Type: txt wing_5degrees.txt (402 Bytes, 4 views)
Ice_Man is offline   Reply With Quote

Old   June 20, 2012, 18:44
Default
  #2
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 460
Rep Power: 18
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
Why do you run extrudeMesh if your case is supposed to be 3D?
lovecraft22 is offline   Reply With Quote

Old   June 21, 2012, 10:42
Default
  #3
New Member
 
Isaac S
Join Date: Jun 2012
Posts: 6
Rep Power: 13
Ice_Man is on a distinguished road
I used extrudeMesh because thats what is used in the wingMotion tutorial I am trying to modify. I also tried skipping the wextrudemesh and create patch steps and running simplefoam but it crashes when create and extrude are not run before it. What kind of solvers/approach do you suggest I use in order to keep the simulation 3D?
Ice_Man is offline   Reply With Quote

Old   June 21, 2012, 10:49
Default
  #4
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 460
Rep Power: 18
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
If you want your case to be a 3D one then you don't need to run neither extrudeMesh nor createPatch which, in fact, are command used to make a 1 element mesh along a chosen direction, giving you 2D results then.

Just skip those two commands.
You may want to have a look at a 3D case, such as the motorbike one for instance.

Also, you defined two faces of your domain (on your blockMeshDict) as empty, that's a special boundary condition used in 2D simulation so you may want to change that condition as well.

I would also suggest you to have a look at the user manual at page U-20 where a 2D mesh is generated for the lid driven flow.
lovecraft22 is offline   Reply With Quote

Old   June 21, 2012, 11:31
Default
  #5
New Member
 
Isaac S
Join Date: Jun 2012
Posts: 6
Rep Power: 13
Ice_Man is on a distinguished road
Thanks for your help lore,
I changed all the empty faces to walls and my mesh looks fine. When I try to run simpleFoam I get the following error message:
--> FOAM FATAL ERROR:
Cannot find file "points" in directory "polyMesh" in times 0 down to constant

From function Time::findInstance(const fileName&, const word&, const IOobject::readOption, const word&)
in file db/Time/findInstance.C at line 188.

FOAM exiting

I believe that the points file that it is looking for is supposed to be created by running extrudemesh. Should I try to find the points file somewhere else or is there a way to get simplefoam to run without that file?
Ice_Man is offline   Reply With Quote

Old   June 21, 2012, 11:35
Default
  #6
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 460
Rep Power: 18
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
Did you run snappyHexMesh -overwrite or just snappyHexMesh?

If you run the latter, then you got with folders 0,1,2,3 and point should be within folder 3, meaning you have to chose that as the starting time for the simulation in your controlDict.
akidess and Ice_Man like this.
lovecraft22 is offline   Reply With Quote

Old   June 21, 2012, 14:42
Default
  #7
New Member
 
Isaac S
Join Date: Jun 2012
Posts: 6
Rep Power: 13
Ice_Man is on a distinguished road
Thanks again that was very helpful I was running snappyhexmesh overwrite. I was able to get simplefoam running after a few more minor changes.
Currently the wingMotion folder is divided into three subfolders; wingMotion_snappyHexMesh, wingMotion2D_simpleFoam and wingMotion2D_pimpleDyMFoam. I copied the 3 file from snappyhexmesh into the wingMotion2D_simplefoam folder and that allowed simplefoam to run. What should I do now? I want to get my object to move through the mesh due to the inlet velocity, I think I want to run pimpleDyMFoam, but I am getting the following error message:
Create time

Create mesh for time = 3

Selecting dynamicFvMesh dynamicMotionSolverFvMesh
Selecting motion solver: displacementLaplacian
Selecting motion diffusion: inverseDistance
--> FOAM Warning :
From function polyBoundaryMesh:atchSet(const wordReList&, const bool) const
in file meshes/polyMesh/polyBoundaryMesh/polyBoundaryMesh.C at line 573
Cannot find any patch names matching wing
Reading field p

Reading field U

Reading/calculating face flux field phi

Selecting incompressible transport model Newtonian
Selecting turbulence model type RASModel
Selecting RAS turbulence model kOmegaSST
kOmegaSSTCoeffs
{
alphaK1 0.85034;
alphaK2 1;
alphaOmega1 0.5;
alphaOmega2 0.85616;
gamma1 0.5532;
gamma2 0.4403;
beta1 0.075;
beta2 0.0828;
betaStar 0.09;
a1 0.31;
c1 10;
}

Reading field rAU if present

No field sources present


PIMPLE: no residual control data found. Calculations will employ 2 corrector loops


Starting time loop

End
Ice_Man is offline   Reply With Quote

Reply

Tags
createpatch, extrude mesh, simplefoam, snappyhexmesh

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
[CAD formats] Creating waterproof STL using snappyHexMesh or salome Tobi OpenFOAM Meshing & Mesh Conversion 58 May 13, 2020 07:01
[snappyHexMesh] Running snappyHexMesh in parallel - optimizing peterhess OpenFOAM Meshing & Mesh Conversion 2 January 3, 2018 03:54
[snappyHexMesh] Tutorial crashes: snappyHexMesh floating point exception. jasv OpenFOAM Meshing & Mesh Conversion 4 May 10, 2016 03:55
[snappyHexMesh] snappyhexmesh doesn't creat mesh in parallel issue? klausb OpenFOAM Meshing & Mesh Conversion 1 March 7, 2015 12:55
[snappyHexMesh] stitchMesh and snappyHexMesh gdbaldw OpenFOAM Meshing & Mesh Conversion 0 December 23, 2009 03:09


All times are GMT -4. The time now is 13:21.