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

Ishii-Zuber drag model in twoPhaseEulerFoam

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

Like Tree2Likes
  • 1 Post By GerhardHolzinger
  • 1 Post By hester

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 5, 2015, 06:35
Default Ishii-Zuber drag model in twoPhaseEulerFoam
  #1
Member
 
Join Date: May 2014
Location: Germany
Posts: 31
Rep Power: 12
hester is on a distinguished road
Hello,

I like to implement the Ishii-Zuber drag model for sparsely distributed fluid particles [1], as used in the CFX implementation [2]. I'm using OpenFoam-2.3.0.

Code:
Foam::tmp<Foam::volScalarField>Foam::dragModels::IshiiZuberExtended::CdRe() const
{
    volScalarField Eo(pair_.Eo());
    volScalarField d(pair_.dispersed().d());
    volScalarField rho(pair_.continuous().rho());
    volScalarField magUr(pair_.magUr());

    volScalarField CdSphere = (24.0 / pair_.Re() * (1 + 0.15 *
      pow(pair_.Re()+ROOTVSMALL , 0.687)));
    volScalarField CdEllipse = ((4.0/3.0) * pow(2 * Eo+ROOTVSMALL , 0.5));
    volScalarField CdCap = (8.0/3.0) * (pair_.Re()/pair_.Re()+ROOTVSMALL);       
    volScalarField Cd = max(CdSphere, min(CdEllipse, CdCap));

    return Cd * (pair_.Re()+ROOTVSMALL);

}
I added ROOTVSMALL because otherweise I would get a segmentation fault at the beginning of my simulation when U = 0 and threrefor Re = 0. I'm simulating a bubble column after Deen with U(initial) = 0.
The value for CdCap is actually just 8/3 but I didn't know how to create a volScalarField from the scalar value.

I get no compiling errors. But my simulation breaks at the first iteration with a floating point error and the following error message:

Code:
#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::sigFpe::sigHandler(int) at ??:?
#2   in "/lib/x86_64-linux-gnu/libc.so.6"
#3  Foam::divide(Foam::Field<double>&, double const&, Foam::UList<double> const&) at ??:?
#4  Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam::operator/<Foam::fvPatchField, Foam::volMesh>(Foam::dimensioned<double> const&, Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > const&) at ??:?
#5  Foam::dragModels::IshiiZuberExtended::CdRe() const at ??:?
#6  Foam::dragModel::K() const at ??:?
#7  Foam::BlendedInterfacialModel<Foam::dragModel>::K() const at ??:?
#8  Foam::twoPhaseSystem::dragCoeff() const at ??:?
#9  
 at ??:?
#10  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#11  
 at ??:?
Gleitkomma-Ausnahme
I don't know what the problem is. The implementation seems fine to me. Maybe someone could give me hint where to look for a solution to my problem.

thanks
hester


[1] Ishii, M. and Zuber, N., “Drag Coefficient and Relative Velocity in Bubbly, Droplet or Particulate Flows”, AIChE J., 25, 843-855, 1979.
[2] http://www.arc.vt.edu/ansys_help/cfx_thry/i1304903.html, Eq. (5-51)-(5-53)
hester is offline   Reply With Quote

Old   February 26, 2015, 04:51
Default
  #2
Senior Member
 
Gerhard Holzinger
Join Date: Feb 2012
Location: Austria
Posts: 339
Rep Power: 28
GerhardHolzinger will become famous soon enoughGerhardHolzinger will become famous soon enough
If you take a close look at the stack-trace you will see that the function Foam::divide was involved in throwing the FPE.
You divide by pair.Re() during your calculation of the drag coefficient.

Most probably, the initial value of pair.Re() evaluates to zero for your initial conditions.

That is why you find code like this max(pair_.Re(), residualRe_) in some of the drag models.
pacopuma likes this.
GerhardHolzinger is offline   Reply With Quote

Old   February 26, 2015, 06:01
Default
  #3
Member
 
Join Date: May 2014
Location: Germany
Posts: 31
Rep Power: 12
hester is on a distinguished road
Thank you for your answer. I saw terms like max(pair_.Re(), residualRe_) in different drag models but I never understood why it was used. I will try it in my drag model. Maybe it works.
hester is offline   Reply With Quote

Old   March 27, 2015, 11:56
Default update
  #4
Member
 
Join Date: May 2014
Location: Germany
Posts: 31
Rep Power: 12
hester is on a distinguished road
Hello Gerhard,

I changed my implementation using residual values for Re and Eo, as suggested. It works now. This is what it looks like:

Code:
Foam::dragModels::IshiiZuberExtended::IshiiZuberExtended
(
    const dictionary& dict,
    const phasePair& pair,
    const bool registerObject
)
:
    dragModel(dict, pair, registerObject),
    residualRe_("residualRe", dimless, dict.lookup("residualRe")),
    residualEo_("residualEo", dimless, dict.lookup("residualEo"))
{}


// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //

Foam::dragModels::IshiiZuberExtended::~IshiiZuberExtended()
{}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

Foam::tmp<Foam::volScalarField> Foam::dragModels::IshiiZuberExtended::CdRe() const
{
    volScalarField Eo(max(pair_.Eo(), residualEo_));
    volScalarField d(pair_.dispersed().d());
    volScalarField rho(pair_.continuous().rho());
    volScalarField magUr(pair_.magUr());
    volScalarField Re(max(pair_.Re(), residualRe_));

    volScalarField CdSphere = (24.0 / Re * (1. + 0.15 * pow(Re , 0.687)));
    volScalarField CdEllipse = ((4.0/3.0) * pow(2. * Eo , 0.5));
    volScalarField CdCap = (8.0/3.0) * Re/Re;
    volScalarField Cd = max(CdSphere, min(CdEllipse, CdCap));

    return Cd * Re;
}
Regards,
hester
BlnPhoenix likes this.
hester is offline   Reply With Quote

Reply

Tags
drag, twophaseeulerfoam

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
twoPhaseEulerFoam - drag coefficient benn OpenFOAM Running, Solving & CFD 1 May 17, 2021 09:29
Yacht Model Drag Analysis ziyasaydam STAR-CCM+ 6 September 8, 2010 04:57
drag calculation of a car model by phoenics mukut Phoenics 2 January 9, 2010 18:07
multiphase model and drag law Yasmail AKARIOUH FLUENT 0 April 29, 2008 07:44
Please help a newbie find the drag on a 3d model David Amer Main CFD Forum 1 March 6, 2002 03:33


All times are GMT -4. The time now is 14:19.