CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Pre-Processing

Sigma surface tension - error when not using default values

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 13, 2019, 05:28
Default Sigma surface tension - error when not using default values
  #1
Member
 
Stefanie Wolf
Join Date: Nov 2018
Location: Aachen
Posts: 32
Rep Power: 3
Stefanie.S.W. is on a distinguished road
Hello everyone,

I am using multiphaseEulerFoam and I would like to use other values than the default value of 0.07 N/m for sigma.

transportProperties
[...]
sigmas
(
(air water) 0.07
(air oil) 0.07
(oil water) 0.07
);

But whenever I change one or all values the simulation stops after the first written time step, I get error messages like:


Quote:

multiphaseEulerFoam >>log.solve
#0 Foam::error:rintStack(Foam::Ostream&) at ??:?
#1 Foam::sigFpe::sigHandler(int) at ??:?
#2 ? in "/lib/x86_64-linux-gnu/libc.so.6"
#3 Foam::multiply(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) at ??:?
#4 void Foam::multiply<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) in "/opt/openfoam6/platforms/linux64GccDPInt32Opt/bin/multiphaseEulerFoam"
#5 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam:perator*<Foam::fvPatchField, Foam::volMesh>(Foam::tmp<Foam::GeometricField<doub le, Foam::fvPatchField, Foam::volMesh> > const&, Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > const&) in "/opt/openfoam6/platforms/linux64GccDPInt32Opt/bin/multiphaseEulerFoam"
#6 Foam::multiphaseSystem::dragCoeffs() const at ??:?
#7 ? in "/opt/openfoam6/platforms/linux64GccDPInt32Opt/bin/multiphaseEulerFoam"
#8 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#9 ? in "/opt/openfoam6/platforms/linux64GccDPInt32Opt/bin/multiphaseEulerFoam"
Floating point exception (core dumped)
This specific error occurred when I changed all sigmas to 0.03. With the default values the simulation runs stable.

Does someone know why I can't change sigma? At some point I need to reduce the surface tension because I will use soapy water.

Thank you for your help!!

kind regards,
Stefanie


I am very uncertain which further information you need, hopefully I guessed right:

0 - alpha.air

Code:
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    location    "0";
    object      alpha.air;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 0 0 0 0];

internalField   uniform 0; 

boundaryField
{
    mischzylinder
    {
        type            alphaContactAngle;
        thetaProperties ( ( oil air ) 90 0 0 0 ( water air ) 90 0 0 0 ( oil water ) 90 0 0 0 );
        value           uniform 1;
    }
    duese
    {
        type            alphaContactAngle;
        thetaProperties ( ( oil air ) 90 0 0 0 ( water air ) 90 0 0 0 ( oil water ) 90 0 0 0 );
        value           uniform 1;
    }
    zylinder
    {
        type            alphaContactAngle;
        thetaProperties ( ( oil air ) 90 0 0 0 ( water air ) 90 0 0 0 ( oil water ) 90 0 0 0 );
        value           uniform 0;
    }
    atmosphere
    {
        type            inletOutlet;
        inletValue      uniform 1;
        value           uniform 1;
    }
}
Alpha.oil and alpha.water are alike:

Code:
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    location    "0";
    object      alpha.lml;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 0 0 0 0];

internalField   uniform 0; 


boundaryField
{
    mischzylinder
    {
        type            zeroGradient;
    }
    duese
    {
        type            zeroGradient;
    }
    zylinder
    {
        type            zeroGradient;
    }
    atmosphere
    {
        type            inletOutlet;
        inletValue      uniform 0;
        value           uniform 0;
    }
}
I also posted a related question here:

multiphaseEulerFoam-transportProperties dict
Stefanie.S.W. is offline   Reply With Quote

Old   July 2, 2020, 03:06
Default
  #2
New Member
 
Join Date: Aug 2016
Posts: 3
Rep Power: 5
betterglobe is on a distinguished road
Did you fix your problem?
The 0.07 N/m default value is probably from the fact that the surface tension of water is 0.0728N/m at 20degC.
I'm not sure about why 0.03 N/m caused a problem. If the IFT drops to zero, the two phases will become mixed soup. So maybe the low IFT is bad for convergence?
betterglobe is offline   Reply With Quote

Reply

Tags
multiphaseeulerfoam, sigma, transportproperties

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Surface tension driven flows: interFoam vs. multiphaseInterFoam dzordz OpenFOAM Programming & Development 2 October 31, 2018 22:26
surface tension problem when using VOF+Solidification&melting models AlvinF FLUENT 3 August 21, 2017 19:44
Surface tension values Apiano FLUENT 2 July 6, 2016 15:10
Access the surface tension force at a patch michielm OpenFOAM Programming & Development 1 December 13, 2013 03:50
[ICEM] Problems with coedge curves and surfaces tommymoose ANSYS Meshing & Geometry 0 August 5, 2011 16:02


All times are GMT -4. The time now is 20:31.