Meshing
Start Gmsh and create the mesh with:
gmsh -3 -optimize t2.geoPossible output
Start Gmsh and create the mesh with:
gmsh -3 -optimize t2.geo
Info : Running 'gmsh -3 -optimize t2.geo' [Gmsh 4.0.4, 1 node, max. 1 thread]
Info : Started on Wed Oct 31 16:19:00 2018
Info : Reading 't2.geo'...
Info : Reading 't1.geo'...
Info : Done reading 't1.geo'
New surfaces '12' and '17'
Info : Done reading 't2.geo'
Info : Meshing 1D...
Info : Meshing curve 1 (Line)
Info : Meshing curve 2 (Line)
Info : Meshing curve 3 (Line)
Info : Meshing curve 4 (Line)
Info : Meshing curve 5 (Line)
Info : Meshing curve 7 (Line)
Info : Meshing curve 8 (Line)
Info : Meshing curve 13 (Line)
Info : Meshing curve 14 (Line)
Info : Meshing curve 15 (Line)
Info : Meshing curve 16 (Line)
Info : Meshing curve 18 (Line)
Info : Meshing curve 19 (Line)
Info : Meshing curve 20 (Line)
Info : Meshing curve 110 (Line)
Info : Meshing curve 111 (Line)
Info : Meshing curve 112 (Line)
Info : Meshing curve 113 (Line)
Info : Meshing curve 114 (Line)
Info : Meshing curve 115 (Line)
Info : Done meshing 1D (0.015625 s)
Info : Meshing 2D...
Info : Meshing surface 1 (Plane, Delaunay)
Info : Meshing surface 11 (Plane, Delaunay)
Info : Meshing surface 12 (Plane, Delaunay)
Info : Meshing surface 17 (Plane, Delaunay)
Info : Meshing surface 119 (Plane, Delaunay)
Info : Meshing surface 121 (Plane, Delaunay)
Info : Meshing surface 123 (Plane, Delaunay)
Info : Meshing surface 125 (Plane, Delaunay)
Info : Meshing surface 138 (Surface, MeshAdapt)
Info : Meshing surface 142 (Surface, MeshAdapt)
Info : Meshing surface 146 (Surface, MeshAdapt)
Info : Done meshing 2D (0.21875 s)
Info : Meshing 3D...
Info : Delaunay Meshing 2 volumes with 1 connected components
Info : Tetrahedrization of 2041 points in 0.03125 seconds
Info : Reconstructing mesh ...
Info : Creating surface mesh...
Info : Identifying boundary edges...
Info : Boundary Recovery...
Info : Writing to GRegion...
Info : Reconstruct time : 0.078125 sec
Info : Found region 129
Info : Found region 130
Info : 0 points created - Worst tet radius is 3.69956 (PTS removed 0 0)
Info : 500 points created - Worst tet radius is 1.13479 (PTS removed 0 0)
Info : 3D point insertion terminated (2809 points created):
Info : - 0 Delaunay cavities modified for star shapeness
Info : - 0 points could not be inserted
Info : - 11002 tetrahedra created in 0.0625 sec. (176032 tets/sec.)
Info : Done meshing 3D (0.1875 s)
Info : Optimizing 3D mesh...
Info : Optimizing volume 129
Info : Opti : STARTS with 2.70000E-03 QBAD 4.45065E-03 QAVG 7.38989E-01
Info : Opti : 0.00 < QUAL < 0.10 : 14 elements
Info : Opti : 0.10 < QUAL < 0.20 : 71 elements
Info : Opti : 0.20 < QUAL < 0.30 : 77 elements
Info : Opti : 0.30 < QUAL < 0.40 : 134 elements
Info : Opti : 0.40 < QUAL < 0.50 : 234 elements
Info : Opti : 0.50 < QUAL < 0.60 : 484 elements
Info : Opti : 0.60 < QUAL < 0.70 : 1178 elements
Info : Opti : 0.70 < QUAL < 0.80 : 1862 elements
Info : Opti : 0.80 < QUAL < 0.90 : 1970 elements
Info : Opti : 0.90 < QUAL < 1.00 : 784 elements
Info : Opti : (159,0,2) = 2.70000E-03 QBAD 2.29759E-01 QAVG 7.53441E-01 ( 0.016 sec)
Info : Opti : (160,0,2) = 2.70000E-03 QBAD 3.00593E-01 QAVG 7.53551E-01 ( 0.016 sec)
Info : Opti : no ill-shaped tets in the mesh ;-)
Info : Opti : 0.00 < QUAL < 0.10 : 0 elements
Info : Opti : 0.10 < QUAL < 0.20 : 0 elements
Info : Opti : 0.20 < QUAL < 0.30 : 0 elements
Info : Opti : 0.30 < QUAL < 0.40 : 121 elements
Info : Opti : 0.40 < QUAL < 0.50 : 220 elements
Info : Opti : 0.50 < QUAL < 0.60 : 505 elements
Info : Opti : 0.60 < QUAL < 0.70 : 1174 elements
Info : Opti : 0.70 < QUAL < 0.80 : 1872 elements
Info : Opti : 0.80 < QUAL < 0.90 : 1984 elements
Info : Opti : 0.90 < QUAL < 1.00 : 786 elements
Info : Optimizing volume 130
Info : Opti : STARTS with 1.80000E-03 QBAD 1.86530E-02 QAVG 7.27254E-01
Info : Opti : 0.00 < QUAL < 0.10 : 16 elements
Info : Opti : 0.10 < QUAL < 0.20 : 37 elements
Info : Opti : 0.20 < QUAL < 0.30 : 58 elements
Info : Opti : 0.30 < QUAL < 0.40 : 87 elements
Info : Opti : 0.40 < QUAL < 0.50 : 151 elements
Info : Opti : 0.50 < QUAL < 0.60 : 352 elements
Info : Opti : 0.60 < QUAL < 0.70 : 776 elements
Info : Opti : 0.70 < QUAL < 0.80 : 1174 elements
Info : Opti : 0.80 < QUAL < 0.90 : 1137 elements
Info : Opti : 0.90 < QUAL < 1.00 : 406 elements
Info : Opti : (110,0,7) = 1.80000E-03 QBAD 2.46333E-01 QAVG 7.43729E-01 ( 0.000 sec)
Info : Opti : (111,0,7) = 1.80000E-03 QBAD 2.83565E-01 QAVG 7.43863E-01 ( 0.000 sec)
Info : Opti : no ill-shaped tets in the mesh ;-)
Info : Opti : 0.00 < QUAL < 0.10 : 0 elements
Info : Opti : 0.10 < QUAL < 0.20 : 0 elements
Info : Opti : 0.20 < QUAL < 0.30 : 1 elements
Info : Opti : 0.30 < QUAL < 0.40 : 75 elements
Info : Opti : 0.40 < QUAL < 0.50 : 139 elements
Info : Opti : 0.50 < QUAL < 0.60 : 362 elements
Info : Opti : 0.60 < QUAL < 0.70 : 781 elements
Info : Opti : 0.70 < QUAL < 0.80 : 1157 elements
Info : Opti : 0.80 < QUAL < 0.90 : 1168 elements
Info : Opti : 0.90 < QUAL < 1.00 : 407 elements
Info : Done optimizing 3D mesh (0.03125 s)
Info : 2809 vertices 15138 elements
Info : Writing 't2.msh'...
Info : Done writing 't2.msh'
Info : Stopped on Wed Oct 31 16:19:01 2018
You can now open t2.msh to see something similar to the following:
Copying mesh
If you recall, the *.din file tells dolfyn to create a *.msh file containing the results. Keeping the same case-name will cause the file to be overwritten. Due to built-in randomness, no 2 meshes created with Gmsh will be the same. For this reason, it is advised to copy the file and rename it for the simulation purposes.
Copying and renaming the file can be performed however you prefer, for example with the following command:
cp t2.msh t2d.mshConverting to dolfyn input
Because dolfyn uses its own set of input files, we now need to convert the mesh into *.cel, a *.vrt, a *.bnd, and optionally an *.inp file.
This is performed using gmsh2dolfyn, and selecting the correct file to convert, in our case: t2d.
gmsh2dolfynPossible output
Start gmsh2dolfyn converter with:
gmsh2dolfyn
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.
Input Gmsh filename, excluding the .msh suffix
t2d
Opening the Gmsh file
File t2d.msh opened
Reading MeshFormat
MeshFormat: 4 0 8
Reading PhysicalNames
Name 2 -> Inlet
Name 3 -> Outlet
Name 1 -> Fluid
Entities
Entity 123 surface 2 Inlet
Entity 142 surface 3 Outlet
Entity 129 volume 1 Fluid
Entity 130 volume 1 Fluid
Physical entities found 4
Reading Nodes
Number of entity blocks: 45 Nodes: 1531
Creating the dolfyn .vrt file
File t2d.vrt opened
Point 1 Node 1
Point 2 Node 1
Point 3 Node 1
Point 4 Node 1
Point 5 Node 1
Point 6 Node 1
Point 7 Node 1
Point 8 Node 1
Point 12 Node 1
Point 16 Node 1
Point 18 Node 1
Point 22 Node 1
Curve 1 Nodes 5
Curve 2 Nodes 12
Curve 3 Nodes 2
Curve 4 Nodes 23
Curve 5 Nodes 23
Curve 7 Nodes 11
Curve 8 Nodes 2
Curve 13 Nodes 23
Curve 14 Nodes 5
Curve 15 Nodes 12
Curve 16 Nodes 2
Curve 110 Nodes 9
Curve 111 Nodes 4
Curve 112 Nodes 9
Curve 113 Nodes 4
Curve 131 Nodes 23
Curve 132 Nodes 3
Curve 133 Nodes 16
Curve 137 Nodes 9
Curve 141 Nodes 6
Surface 1 Nodes 86
Surface 11 Nodes 49
Surface 12 Nodes 86
Surface 119 Nodes 72
Surface 121 Nodes 266
Surface 123 Nodes 50
Surface 125 Nodes 21
Surface 138 Nodes 253
Surface 142 Nodes 22
Surface 146 Nodes 74
Surface 151 Nodes 65
Volume 129 Nodes 177
Volume 130 Nodes 95
Nodes written 1531
Total Gmsh elements to be read in: 5446
Creating the dolfyn .cel and .bnd files 14 23
File t2d.cel opened
File t2d.bnd opened
Element 123 Inlet Type 2 125
Element 142 Outlet Type 2 66
Element 129 Fluid Type 4 3035
Element 130 Fluid Type 4 2220
Triangle boundaries: 191
Tetrahedral cells: 5255
Writing the .inp file
File t2d.inp opened
inp: 2 Inlet T
inp: 3 Outlet T
Done gmsh2dolfyn 2018
Running Pre-Processor
Now we will run the pre-processor.
dolgeo -s 1.0 -b t2dIf no options are given with the dolgeo command, you will be prompted for them. Fill in case name t2d, scaling factor of 1.0 (default) and bin as format of geometry file.
Possible output
The pre-processor is run with:
dolgeo
Dolfyn PreProcessor
Input casename:
t2d
Using t2d as input
Opening vertex file
Initialise vertex list
. . .
Region ID: 2 => Inlet
Region ID: 3 => Outlet
Type 1 regions found: 2 3
WARNING: check inp-file
Enter scaling factor (1.0):
1.0
Enter format of geometry file (bin|ascii):
bin
Using: 1.00000000 binary
Dump binary geometry file
Done
Running Simulation
Finaly we will run the dolfyn simulation.
dolfyn t2dIf no case name is inputted directly, you will be prompted. If so, enter case name t2d.
Possible output
The pre-processor is run with:
dolfyn
This is dolfyn version 0.608
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
Enter case:
t2d
Using case: t2d
Calling dolfyn t2d .dge
t2d.dge binary
.
.
.
*** CONVERGENCE *** 9.43839725E-04
Opening restart file
File t2d.rst
Restartfile 400 written
Writing VTK data file... t2d.vtk
Done
Writing Full Gmsh file...
Done
Maximum change in PP: 1.39341195E-04 2.60319840E-02 1.00000005E-03
Arrays cleaned up
Done t2d
Bye!
That’s it! Now all the calculations have been carried out, we can start to analyze the output.