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

Pipe flow

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 21, 2006, 21:36
Default Hello I have trying to fo c
  #1
shuo
Guest
 
Posts: n/a
Hello

I have trying to fo calculation for a laminar pipe flow. I fot results from using FLuent and wanted to compare them with those obtained using icoFoam. The mesh was imported sucessfully and compiled without errors to my knowledge.

Time = 0.5

Mean and max Courant Numbers = 4.1213e+77 1.56978e+79
BICCG: Solving for Ux, Initial residual = 1, Final residual = 30.5736, No Iterations 1001
BICCG: Solving for Uy, Initial residual = 1, Final residual = 37.0907, No Iterations 1001
ICCG: Solving for p, Initial residual = 1, Final residual = 4001.94, No Iterations 5001
time step continuity errors : sum local = 8.45863e+91, global = -3.96813e+87, cumulative = -3.96813e+87
ICCG: Solving for p, Initial residual = 1, Final residual = 0.689595, No Iterations 5001
time step continuity errors : sum local = 5.12229e+99, global = -1.02924e+96, cumulative = -1.02924e+96
ExecutionTime = 1.34 s ClockTime = 2 s

End


I get the time directories: 0 0.1 0.2 0.3 0.4 0.5 constant system VTK

However when i tried to execute foamToVTK to see the results in Paraview I get error messages.

/*---------------------------------------------------------------------------*\
| ========= | |
| \ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \ / O peration | Version: 1.3 |
| \ / A nd | Web: http://www.openfoam.org |
| \/ M anipulation | |
\*---------------------------------------------------------------------------*/

Exec : foamToVTK . pipe
Date : Sep 22 2006
Time : 12:31:50
Host : bro835a-cm
PID : 8753
Root : /home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam
Case : pipe
Nprocs : 1
Create time

Deleting old VTK files in "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/ pipe/VTK"

Time constant
volScalarFields :
volVectorFields :
pointScalarFields :
pointVectorFields :

Internal : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/p ipe_0.vtk"
Original cells:500 points:1212 Additional cells:0 additional points:0

Patch : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/O UTLET/OUTLET_0.vtk"
Patch : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/C ENTERLINE/CENTERLINE_0.vtk"
Patch : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/W ALL/WALL_0.vtk"
Patch : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/I NLET/INLET_0.vtk"
Patch : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/f rontAndBackPlanes/frontAndBackPlanes_0.vtk"
Time 0
volScalarFields : p
volVectorFields : U
pointScalarFields :
pointVectorFields :

Internal : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/p ipe_1.vtk"
Patch : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/O UTLET/OUTLET_1.vtk"
Patch : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/C ENTERLINE/CENTERLINE_1.vtk"
Patch : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/W ALL/WALL_1.vtk"
Patch : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/I NLET/INLET_1.vtk"
Patch : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/f rontAndBackPlanes/frontAndBackPlanes_1.vtk"
Time 0.1
volScalarFields : p
volVectorFields : U
pointScalarFields :
pointVectorFields :

Internal : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/p ipe_2.vtk"
Patch : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/O UTLET/OUTLET_2.vtk"
Patch : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/C ENTERLINE/CENTERLINE_2.vtk"
Patch : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/W ALL/WALL_2.vtk"
Patch : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/I NLET/INLET_2.vtk"
Patch : "/home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/VTK/f rontAndBackPlanes/frontAndBackPlanes_2.vtk"
Time 0.2
volScalarFields : p


--> FOAM FATAL IO ERROR : wrong token type - expected Scalar found on line 31 th e word 'nan'

file: /home/li077/OpenFOAM/li077-1.3/run/tutorials/icoFoam/pipe/0.2/U at line 31 .

From function operator>>(Istream&, Scalar&)
in file /home/dm2/henry/OpenFOAM/OpenFOAM-1.3/src/OpenFOAM/lnInclude/Scalar. C at line 85.

FOAM exiting
Here is the contents of VTK folder

CENTERLINE frontAndBackPlanes INLET OUTLET pipe_0.vtk pipe_1.vtk pipe_2.vtk WALL

SHuo
  Reply With Quote

Old   September 22, 2006, 01:57
Default Hello It blows up, look at yo
  #2
New Member
 
Aurelia Cure
Join Date: Mar 2009
Location: Lund, Sweden
Posts: 18
Rep Power: 17
aurelia is on a distinguished road
Hello
It blows up, look at your courant numbers:

Mean and max Courant Numbers = 4.1213e+77 1.56978e+79

VtK can't convert your files because there is "nan" in these files, wich means that you have something wrong going on in your computation
You should have some nonorthogonal corrector if your geometry is a pipe

Aurelia
aurelia is offline   Reply With Quote

Old   September 22, 2006, 02:28
Default Hi, decrease the Co number
  #3
atzaru
Guest
 
Posts: n/a
Hi,

decrease the Co number (in the tuorial you have a nice example on how to calculate the nedded time step)

If your problem is a steady state one u can go the simpleFoam solver

Atzaru
  Reply With Quote

Reply


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
3d Pipe Flow. Sean Cody FLUENT 3 March 18, 2006 09:50
Pipe flow ! Sun FLUENT 0 November 18, 2004 01:29
Pipe flow Sohail Ahmed FLUENT 4 March 20, 2004 05:32
Pipe Flow Ajay S Parihar Main CFD Forum 1 April 3, 2002 07:48
Pipe flow John Grimm Main CFD Forum 8 March 11, 2002 12:15


All times are GMT -4. The time now is 05:10.