[sourav90]

The icoUncoupledKinematicParcelFoam or particleFoam solver does in include non Newtonian fluid models (in opefoam.com version 2012 and openfoam.org 8 versions, respectively). However, I need to track particles inside a nozzle at steady state laminar flow with power law fluid. I have the steady state velocity profile (after running simpleFoam), which I can use for the particle tracking.

But I not absolutely sure of the viscosity model that needs to be provided.

❯FOAM_TUTORIALS/lagrangian/particleFoam/hopper/hopperInitialState/constant/transportProperties

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  8
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "constant";
    object      transportProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

rhoInf          [1 -3 0 0 0 0 0] 1.2;

transportModel  Newtonian;

nu              [0 2 -1 0 0 0 0] 1e-05;

// ************************************************************************* //

Such as,

1. In the tutorial of particleFoam, is it for the fluid or for the particles?
2. If partcleFoam implementation says it does not influence the fluid flow, then why do we need to provide a viscosity model, since the velocity field U is already provided and not changing?

I tried providing non Newtonian viscosity model in the transportProperties of particleFoam, but it failed.

❯ particleFoam
/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  8
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
Build  : 8
Exec   : particleFoam
Date   : Apr 13 2021
Time   : 13:47:55
Host   : "archLinux2"
PID    : 30850
I/O    : uncollated
Case   : /home/massisenergy/autoMount/Data_Documents/Dox_ownCloud/openFoamDataSR/E3DBP_Nozzle/CFD_E3DBP_PauloA_SM/PAA_Blunted_Nordson7018358_fR1.5microlitre/PAA_Blend1_deltaX0.02Y0.025_simpleFOAM/PAAB1_deltaX.02Y.025_particleFoamNewtonian
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0


Reading g
Reading field U

Reading/calculating face flux field phi

Selecting incompressible transport model powerLaw


--> FOAM FATAL IO ERROR: 
keyword grad(U) is undefined in dictionary "/home/.../system/fvSchemes/gradSchemes"

file: /home/.../system/fvSchemes/gradSchemes from line 25 to line 25.

    From function const Foam::entry& Foam::dictionary::lookupEntry(const Foam::word&, bool, bool) const
    in file db/dictionary/dictionary.C at line 799.

FOAM exiting

This query had been raised earlier also, but without any satisfactory explanation.

[sourav90]

Originally Posted by sourav90

--> FOAM FATAL IO ERROR: 
keyword grad(U) is undefined in dictionary "/home/.../system/fvSchemes/gradSchemes"

file: /home/.../system/fvSchemes/gradSchemes from line 25 to line 25.

    From function const Foam::entry& Foam::dictionary::lookupEntry(const Foam::word&, bool, bool) const
    in file db/dictionary/dictionary.C at line 799.

FOAM exiting

I figured out that I needed a small change, like this:

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  8
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "system";
    object      fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
    default         none;
}

gradSchemes
{
    default         Gauss linear;//none;
}


divSchemes
{
    default         none;
}

laplacianSchemes
{
    default         none;
}

interpolationSchemes
{
    default         linear;
}

//************************************************************************* //

Then it proceeds without error, and looking at the particle distribution in my geometry, it looks fine .

[sourav90]

Originally Posted by sourav90

The icoUncoupledKinematicParcelFoam or particleFoam solver does in include non Newtonian fluid models (in opefoam.com version 2012 and openfoam.org 8 versions, respectively). However, I need to track particles inside a nozzle at steady state laminar flow with power law fluid. I have the steady state velocity profile (after running simpleFoam), which I can use for the particle tracking.

But I not absolutely sure of the viscosity model that needs to be provided.

❯FOAM_TUTORIALS/lagrangian/particleFoam/hopper/hopperInitialState/constant/transportProperties

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  8
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "constant";
    object      transportProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

rhoInf          [1 -3 0 0 0 0 0] 1.2;

transportModel  Newtonian;

nu              [0 2 -1 0 0 0 0] 1e-05;

// ************************************************************************* //

Such as,

1. In the tutorial of particleFoam, is it for the fluid or for the particles?
2. If partcleFoam implementation says it does not influence the fluid flow, then why do we need to provide a viscosity model, since the velocity field U is already provided and not changing?

This query had been raised earlier also, but without any satisfactory explanation.

However I'm still didn't find any answer for this. Anyone familiar / knowledgeable about these, can please reply for me and the future users?

[oswald]

Hi,


1) It is for the fluid.
2) Some of the forces acting on the particle do depend on the fluid viscosity. So you need to have it in order to correctly calculate the particle motion.