Meshing
Start Gmsh and create the mesh with:
gmsh -3 man.geo -optimize_netgen man.geoNote, optimizing is necessary!
Possible output
Start Gmsh and create the mesh with:
gmsh -3 man.geo -optimize_netgen man.geo
Info : Running 'gmsh -3 man.geo -optimize_netgen man.geo' [Gmsh 4.0.4, 1 node, max. 1 thread]
Info : Started on Wed Nov 21 16:56:27 2018
Info : Reading 'man.geo'...
Info : Reading 'man_model.stl'...
Info : 13898 facets in solid 0
. . .
Info : Writing 'man.msh'...
Info : Done writing 'man.msh'
Info : Stopped on Wed Nov 21 16:56:43 2018
Opening man.msh won’t be very helpful, but will show something similar to:
Unfortunately, this mesh is not easy to check and inspect.
Copying mesh
Again, to make sure the mesh file will not be overwritten by the results, we copy and rename the files:
cp man.msh mand.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: mand.
gmsh2dolfyn mandPossible output
Start gmsh2dolfyn converter with:
gmsh2dolfyn mand
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 mand.msh opened
Reading MeshFormat
MeshFormat: 4 0 8
Reading PhysicalNames
Name 2 -> Man
Name 3 -> Floor
Name 4 -> Inlet
Name 5 -> Outlet
Name 6 -> Walls
Name 1 -> Fluid
Entities
Entity 1 surface 2 Man
. . .
Entity 2 volume 1 Fluid
Physical entities found 8
Reading Nodes
Number of entity blocks: 28 Nodes: 16324
Creating the dolfyn .vrt file
File mand.vrt opened
Point 1 Node 1
. . .
Volume 2 Nodes 7711
Nodes written 16324
Gmsh 4: Total Gmsh Entity Blocks to be read in: 8
Gmsh 4: Total Gmsh elements to be read in: 88306
Creating the dolfyn .cel and .bnd files 14 23
File mand.cel opened
File mand.bnd opened
Element 1 Man Type 2 13898
. . .
Element 2 Fluid Type 4 71088
Triangle boundaries: 17218
Tetrahedral cells: 71088
Writing the .inp file
File mand.inp opened
inp: 2 Man T
inp: 3 Floor T
inp: 4 Inlet T
inp: 5 Outlet T
inp: 6 Walls T
Done gmsh2dolfyn 2018
Running Pre-Processor
Now we will run the pre-processor, with scaling factor of 0.1. Note that man.geo was made with 10x larger units.
dolgeo -s 0.1 -b mandIf no options are given with the dolgeo command, you will be prompted for them. Fill in case name mand, scaling factor of 0.1 (! important) and bin as format of geometry file.
Possible output
The pre-processor is run with:
dolgeo -s 0.1 -b mand
Dolfyn PreProcessor
mand 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: 0.100000001 binary
Dump binary geometry file
Done
Running Simulation
Finaly we will run the dolfyn simulations.
dolfyn mandIf no case name is inputted directly, you will be prompted. If so, enter case name mand.
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.