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

CrossPowerLaw

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

Reply
 
LinkBack Thread Tools Display Modes
Old   October 6, 2008, 07:45
Default Hi all, I want to simulate
  #1
New Member
 
Volker Ludewig
Join Date: Mar 2009
Location: Chemnitz, saxony, germany
Posts: 12
Rep Power: 8
tommie is on a distinguished road
Hi all,

I want to simulate a flow through vent.
The flow velocity is very small. So Reynold No. is below 2300 and I should have a laminar flow.
The behavior of the fluid is similar to "Shear thinning" fluids.
In the first step I simulated a Newtonian flow. I applied SimpleFoam and all was really fine.
Now I am testing the CrossPower- law and
at the moment at my wits' end:

As soon as I set CrossPower- exponent n <> 0 then I get the following error:

/*---------------------------------------------------------------------------*\
| ========= | |
| \ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \ / O peration | Version: 1.4.1 |
| \ / A nd | Web: http://www.openfoam.org |
| \/ M anipulation | |
\*---------------------------------------------------------------------------*/

Exec : simpleFoam /opt/OpenFOAM/volker-1.4.1/run Testsimplefoam2
Date : Oct 05 2008
Time : 23:53:16
Host : localhost
PID : 5472
Root : /opt/OpenFOAM/volker-1.4.1/run
Case : Testsimplefoam2
Nprocs : 1
Create time

Create mesh for time = 0

Reading field p

Reading field U

Reading/calculating face flux field phi

Selecting incompressible transport model CrossPowerLaw
#0 Foam::error::printStack(Foam:stream&) in "/home/volker/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/volker/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so"
#2 Uninterpreted: [0xffffe420]
#3 pow in "/lib/i686/libm.so.6"
#4 Foam::pow(Foam::Field<double>&, Foam::UList<double> const&, double const&) in "/home/volker/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so"
#5 Foam::tmp<foam::geometricfield<double,> > Foam::pow<foam::fvpatchfield,>(Foam::tmp<foam::geo metricfield<double,> > const&, Foam::dimensioned<double> const&) in "/home/volker/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libincompressibleTurbule nceModels.so"
#6 Foam::viscosityModels::CrossPowerLaw::calcNu() const in "/home/volker/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libincompressibleTranspo rtModels.so"
#7 Foam::viscosityModels::CrossPowerLaw::CrossPowerLa w(Foam::word const&, Foam::dictionary const&, Foam::GeometricField<foam::vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double,> const&) in "/home/volker/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libincompressibleTranspo rtModels.so"
#8 Foam::viscosityModel::adddictionaryConstructorToTa ble<foam::viscositymodels::cro sspowerlaw>::New(Foam::word const&, Foam::dictionary const&, Foam::GeometricField<foam::vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double,> const&) in "/home/volker/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libincompressibleTranspo rtModels.so"
#9 Foam::viscosityModel::New(Foam::word const&, Foam::dictionary const&, Foam::GeometricField<foam::vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double,> const&) in "/home/volker/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libincompressibleTranspo rtModels.so"
#10 Foam::singlePhaseTransportModel::singlePhaseTransp ortModel(Foam::GeometricField< foam::vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double,> const&) in "/home/volker/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libincompressibleTranspo rtModels.so"
#11 main in "/home/volker/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linuxGccDPOpt/simpleFoam"
#12 __libc_start_main in "/lib/i686/libc.so.6"
#13 Foam::regIOobject::readIfModified() in "/home/volker/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linuxGccDPOpt/simpleFoam"


What could be wrong??

I am thankful about all suggestions.

Kind regards
tommie is offline   Reply With Quote

Old   October 7, 2008, 00:41
Default Hi, Try to check your synt
  #2
New Member
 
zhiwei liu
Join Date: Mar 2009
Posts: 22
Rep Power: 8
lzw2003 is on a distinguished road
Hi,

Try to check your syntax in TransportModel.
Maybe you have these errors:
(1)lost a bracket or a semicolon;
(2) m m [0 0 1 0 0 0 0] not m m [0 0 0 0 0 0 0];
lzw2003 is offline   Reply With Quote

Old   October 8, 2008, 04:34
Default Yes it works. The vector fo
  #3
New Member
 
Volker Ludewig
Join Date: Mar 2009
Location: Chemnitz, saxony, germany
Posts: 12
Rep Power: 8
tommie is on a distinguished road
Yes it works.

The vector for the dimensions was wrong.

Many thanks.

I applied SimpleFoam in FoamX the GUI (graphic user interface) of OpenFoam.
There is a programming error. The program produces script code.
The dimension vectors in the script code for CrossPowerLaw and BirdCarreauLaw are without dimensions:

Wrong
CrossPowerLawCoeffs
{
nu0 nu0 [0 2 -1 0 0 0 0] ...;
nuInf nuInf [0 2 -1 0 0 0 0] ...;
m <> [0 0 0 0 0 0 0] ...;
n <> [0 0 0 0 0 0 0] ...;
}
BirdCarreauCoeffs
{
nu0 nu0 [0 2 -1 0 0 0 0] ...;
nuInf nuInf [0 2 -1 0 0 0 0] ...;
k <> [0 0 0 0 0 0 0] ...;
n <> [0 0 0 0 0 0 0] ...;
}

Works
CrossPowerLawCoeffs
{
nu0 nu0 [0 2 -1 0 0 0 0] ...;
nuInf nuInf [0 2 -1 0 0 0 0] ...;
m m [0 0 1 0 0 0 0] ...;
n n [0 0 0 0 0 0 0] ...;
}
BirdCarreauCoeffs
{
nu0 nu0 [0 2 -1 0 0 0 0] ...;
nuInf nuInf [0 2 -1 0 0 0 0] ...;
k k [0 0 1 0 0 0 0] ...;
n n [0 0 0 0 0 0 0] ...;
}
dimension vector general:
[a b c d e f g]

a Mass kilogram in kg
b Length metre in m
c Time second in s
d Temperature Kelvin in K
e Quantity moles in mol
f Current ampere in A
g Luminous intensity candela in cd

Example for nu in m^2/s: nu [0 2 -1 0 0 0 0] 0.0005
tommie is offline   Reply With Quote

Old   August 1, 2009, 21:17
Default
  #4
Senior Member
 
Sandy Lee
Join Date: Mar 2009
Posts: 207
Rep Power: 9
sandy is on a distinguished road
Hi everybody, where can I find those values nu0, nuInf, m, n, k to different phase names at different temperatures about CrossPowerLawCoeffs and BirdCarreauCoeffs??
sandy is offline   Reply With Quote

Old   January 14, 2010, 07:11
Default
  #5
New Member
 
June
Join Date: Dec 2009
Posts: 18
Rep Power: 7
examosty is on a distinguished road
Quote:
Originally Posted by sandy View Post
Hi everybody, where can I find those values nu0, nuInf, m, n, k to different phase names at different temperatures about CrossPowerLawCoeffs and BirdCarreauCoeffs??
hi everyone,
i've also met this problem. There's so many keywords in openfoam, it's difficult to find out what do they mean. Is there guide for they too?
examosty is offline   Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 22:08.