Meshing
Start Gmsh and create the mesh with:
gmsh -3 model.geoPossible output
Start Gmsh and create the mesh with:
gmsh -3 model.geo
Info : Running 'gmsh -3 model.geo' [Gmsh 4.0.4, 1 node, max. 1 thread]
Info : Started on Sat Nov 24 20:19:43 2018
Info : Reading 'model.geo'...
Info : Done reading 'model.geo'
. . .
Info : Writing 'model.msh'...
Info : Done writing 'model.msh'
Info : Stopped on Sat Nov 24 20:19:44 2018
Opening model.msh will show something similar to:
Copying mesh
Again, to make sure the mesh file will not be overwritten by the results, we copy and rename the files:
cp model.msh karman.mshConverting to dolfyn input
We now convert the mesh into *.cel, a *.vrt, a *.bnd, and optionally an *.inp file using gmsh2dolfyn, and selecting the correct file to convert, in our case: karman.
gmsh2dolfyn karmanPossible output
Start gmsh2dolfyn converter with:
gmsh2dolfyn karman
Gmsh2Dolfyn: Converts a Gmsh mesh file to Dolfyn format.
Input must be in Gmsh version 2.0, 2.1, 2.2 or 4 ascii format.
Opening the Gmsh file
File karman.msh opened
Reading MeshFormat
MeshFormat: 4 0 8
Reading PhysicalNames
Name 2 -> Wall
Name 3 -> In
Name 4 -> Out
Name 5 -> Bottom
Name 6 -> Top
Name 7 -> Front
Name 8 -> Back
Name 1 -> Fluid
Entities
Entity 1 surface 8 Back
. . .
Entity 16 volume 1 Fluid
Physical entities found 68
Reading Nodes
Number of entity blocks: 204 Nodes: 34460
Creating the dolfyn .vrt file
File karman.vrt opened
Point 1 Node 1
. . .
Surface 409 Nodes 4321
Nodes written 34460
Gmsh 4: Total Gmsh Entity Blocks to be read in: 68
Gmsh 4: Total Gmsh elements to be read in: 51380
Creating the dolfyn .cel and .bnd files 14 23
File karman.cel opened
File karman.bnd opened
Element 1 Back Type 3 160
. . .
Element 16 Fluid Type 5 4500
Quad boundaries: 34460
Hexahedral cells: 16920
Writing the .inp file
File karman.inp opened
inp: 2 Wall T
inp: 3 In T
inp: 4 Out T
inp: 5 Bottom T
inp: 6 Top T
inp: 7 Front T
inp: 8 Back T
Done gmsh2dolfyn 2018
Running Pre-Processor
dolgeo -s 1.0 -b karmanIf no options are given with the karman command, you will be prompted for them. Fill in case name mand, scaling factor of 1.0 and bin as format of geometry file.
Possible output
The pre-processor is run with:
dolgeo -s 0.1 -b karman
Dolfyn PreProcessor
karman T T T F
Using command line arguments
Using mand as input
Opening vertex file
Initialise vertex list
. . .
Region ID: 2 => Man
Region ID: 3 => Floor
Region ID: 4 => Inlet
Region ID: 5 => Outlet
Region ID: 6 => Walls
Type 1 regions found: 5 6
WARNING: check inp-file
Using: 1.000000001 binary
Dump binary geometry file
Done
Running Simulation
Finaly we will run the dolfyn simulations.
dolfyn karmanIf no case name is inputted directly, you will be prompted. If so, enter case name karman.
Possible output
The pre-processor is run with:
dolfyn mand
This is dolfyn version 0.607
Copyright(C) 2002-2016 Cyclone Fluid Dynamics BV
NL-5583 XM, Waalre, The Netherlands
see http://www.cyclone.nl and https://www.dolfyn.net
Using Sparsekit2 by Yousef Saad
(C) 2005, the Regents of the University of Minnesota
Modules with patches (C) 2004-2010 by B. Tuinstra
see http://www.home.zonnet.nl/bouke_1/dolfyn
Tecplot interface (tecplt.f90) (C) 2006-2012 by
S.B. Kuang, UNSW, Sydney, Australia
VTK interface updated (C) 2007 by J. Jacobs
Static boundary conditions (C) 2011 by J. JoJo
MKL contributions and suggestions by Runar
Using case: mand
Calling dolfyn mand .dge
mand.dge binary
. . .
Number of requested steps done. 200
Opening restart file
File mand.rst
Restartfile 400 written
Writing VTK data file... mand.vtk
Done
Writing Full Gmsh file...
Done
Maximum change in PP: 1.82208765 3.45761771E-04 9.99999975E-06
Arrays cleaned up
Done mand
Bye!
That’s it! Now all the calculations have been carried out, we can start to analyze the output.