CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

foam-extend 4.1 GGI check

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 23, 2021, 14:46
Default foam-extend 4.1 GGI check
  #1
New Member
 
Andrea
Join Date: Dec 2017
Posts: 9
Rep Power: 8
andreaRocca is on a distinguished road
Hello Folks


I'm working with foam-extend simulating a Francis turbine and I have problems to get a solution.



In the CAD the surfaces composing the interfaces perfectly match each other.

After meshed (discretization error) the differences between areas at the interfaces are:

Spiral-GuideVanes: Diff = -1.54116647556601e-05
Bulb-DraftTube: Diff = 2.25976241261805e-05


According to your experience, is it enough an area difference of O(e-05) for GGI (or mixing plane) interfaces?



Bests
andreaRocca is offline   Reply With Quote

Old   February 24, 2021, 05:20
Default
  #2
Senior Member
 
Hrvoje Jasak
Join Date: Mar 2009
Location: London, England
Posts: 1,906
Rep Power: 33
hjasak will become famous soon enough
This should not be a problem - compare the error in area between the two surfaces with respect to the flux error.


Can you post the whole message?
__________________
Hrvoje Jasak
Providing commercial FOAM/OpenFOAM and CFD Consulting: http://wikki.co.uk
hjasak is offline   Reply With Quote

Old   February 24, 2021, 05:35
Default
  #3
New Member
 
Andrea
Join Date: Dec 2017
Posts: 9
Rep Power: 8
andreaRocca is on a distinguished road
Thank you for reply Prof. Jasak.

The message is the following:



GGI pair (SP-GV, GV-SP)
Area: 0.254671269026831 0.254686680691586 Diff = -1.54116647556601e-05 or 0.00605122525991961 %
Flux: 0.949992608907554 0.950088338717345 Diff = -9.57298097908899e-05 or 0.010075885145599 %
GGI pair (BULB-DT, DT-BULB)
Area: 0.138815526804067 0.138792929179941 Diff = 2.25976241261805e-05 or 0.0162788879936147 %
Flux: 0.972494692318502 0.972510217271029 Diff = -1.55249525264356e-05 or 0.0015963793748101 %


Regarding the last interface (mixing-plane) the mixing plane check is not working in parallel (this can be verified also running the tutorial "axialTurbine_mixingPlane").



I made the grids using Numeca AG5 and Omnis. The checkMesh looks fine.




Create time

Create polyMesh for time = 0

Initializing the GGI interpolator between master/shadow patches: SP-GV/GV-SP
Initializing the GGI interpolator between master/shadow patches: BULB-DT/DT-BULB
Time = 0

Mesh stats
all points: 22230489
live points: 13966149
all faces: 46481093
live faces: 38339883
internal faces: 35820020
cells: 12196229
boundary patches: 27
point zones: 0
face zones: 6
cell zones: 4

Overall number of cells of each type:
hexahedra: 11986443
prisms: 0
wedges: 0
pyramids: 0
tet wedges: 0
tetrahedra: 0
polyhedra: 209786

Checking topology...
Boundary definition OK.
Point usage OK.
Upper triangular ordering OK.
Face vertices OK.
*Number of regions: 4
The mesh has multiple regions which are not connected by any face.
<<Writing region information to "0/cellToRegion"
Nuumber of cells per region:
0 330992
1 0
2 0
3 0


Checking geometry...
This is a 3-D mesh
Overall domain bounding box (-0.7879466659 -1.671217118 -0.2864486732) (0.8220821991 4.442373826 3.74207617)
Mesh (non-empty, non-wedge) directions (1 1 1)
Mesh (non-empty) directions (1 1 1)
Mesh (non-empty, non-wedge) dimensions 3
Boundary openness (-7.36175726854743e-13 -2.65983934844024e-12 2.58673887309245e-12) Threshold = 1e-06 OK.
Max cell openness = 5.15135387404077e-08 OK.
Max aspect ratio = 267.233167283032 OK.
Minumum face area = 3.35187928762322e-09. Maximum face area = 0.011201607594839. Face area magnitudes OK.
Min volume = 3.13556677637343e-12. Max volume = 0.00116740721267175. Total volume = 3.08841375862224. Cell volumes OK.
Mesh non-orthogonality Max: 72.648044449205 average: 18.5441847118136 Threshold = 70
*Number of severely non-orthogonal faces: 22.
Non-orthogonality check OK.
Writing 22 non-orthogonal faces to set nonOrthoFaces
Face pyramids OK.
Max skewness = 2.77047715280581 OK.

Mesh OK.

End
andreaRocca is offline   Reply With Quote

Old   August 22, 2022, 11:01
Default
  #4
New Member
 
Jianfeng
Join Date: Apr 2021
Posts: 11
Rep Power: 5
jennyjian is on a distinguished road
Hi, did you use the ggi interface in parallel mode ? I find the initialization takes too much time when I use ggi interface in parallel? Do I need to decompose the mesh in another way ? Thanks!
jennyjian is offline   Reply With Quote

Reply

Tags
foam-extend 4.1, ggi, interfaces, mixing-plane

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
Block coupling three equations using foam extend 4.1 ELwardi OpenFOAM Programming & Development 2 March 19, 2019 10:35
[blockMesh] BlockMesh FOAM warning gaottino OpenFOAM Meshing & Mesh Conversion 7 July 19, 2010 14:11
Problems in compiling paraview in Suse 10.3 platform chiven OpenFOAM Installation 3 December 1, 2009 07:21
Problem with rhoSimpleFoam matteo_gautero OpenFOAM Running, Solving & CFD 0 February 28, 2008 06:51
[Gmsh] Import gmsh msh to Foam adorean OpenFOAM Meshing & Mesh Conversion 24 April 27, 2005 08:19


All times are GMT -4. The time now is 06:32.