[Sid!]

Hi Foamers,

I am using the reactingTwoPhaseEulerFoam solver in OpenFOAM v1612+ to simulate boiling of water in a pipe.
The geometry is a horizontal pipe of 4 m length and 15.4 mm diameter. I simulate only half of the pipe, so one of the boundary is a symmetry plane and the other boundary is a heated wall. I simulated single phase flow of water in the pipe and used the velocity, k, epsilon and nut at the outlet as the inlet for my multiphase simulation. The inlet velocity for the single phase simulation is 1 m/s and pressure is 45 bar. The geometry and the mesh in the single phase and multiphase simulations are the same.

In the multiphase simulation, the heat flux at the wall is 5.7e5 W/m2. Chemistry and combustion are switched off. Turbulence for both phases is modelled using k epsilon model.

The multiphase simulations run without any complaints but the temperature and the pressure increases above the prescribed saturation values and no vapour is formed. I am unsure as to if my pressure boundary condition and the phase properties are correct. I would appreciate if someone could have a look at them and let me know if anything is incorrect.

For reference I have attached the p, p_rgh and thermophysical properties file. The thermodynamic and transport properties correspond to 45 bar. I have used the prghPressure boundary condition at the exit and estimated the pressure drop to be about 0.3 bar. Hence the outlet pressure is 44.7 bar. Please let me know if this boundary condition is correct.

I have also attached the checkMesh log file, phase properties, fvSchemes and fvSoution file.

On a side note, has anyone managed to simulate the Bartolomej boiling experiment using either the twoPhaseEulerFoam or the reactingTwoPhaseEulerFoam solver?

Sorry for the long post. I would appreciate if anyone could help me with my simulations. If my question is unclear or if any further information is needed, kindly let me know in the comments.

Regards,
Sid

*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  plus                                  |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    location    "0";
    object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 4470000;

boundaryField
{
    inlet
    {
        type            calculated;
        value           $internalField;
    }
    outlet
    {
        type            calculated;
        value           $internalField;
    }
    symmetry
    {
        type            symmetryPlane;
    }
    heatedWall
    {
        type            calculated;
        value           $internalField;
    }
    defaultFaces
    {
        type            empty;
    }
}


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

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  plus                                  |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    location    "5";
    object      p_rgh;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 4470000;

boundaryField
{
    inlet
    {
        type            fixedFluxPressure;
    }
    outlet
    {
        type            prghPressure; //prghPressure;
        //value		uniform 0;
	p               uniform 4470000;
        value           uniform 4470000;
    }
    symmetry
    {
        type            symmetryPlane;
    }
    heatedWall
    {
        type            zeroGradient;
    }
    defaultFaces
    {
        type            empty;
    }
}


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

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  plus                                  |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "constant";
    object      thermophysicalProperties.liquid;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

thermoType
{
    type            heRhoThermo;
    mixture         multiComponentMixture;
    transport       polynomial;
    thermo          hPolynomial;
    equationOfState icoPolynomial;
    specie          specie;
    energy          sensibleEnthalpy;
}

dpdt no;

species
(
    water
);

inertSpecie water;

"(mixture|H2O|water)"
{
    specie
    {
        nMoles          1;
        molWeight       18.0153;
    }
    equationOfState // rho = rho(T)
    {
	rhoCoeffs<8>	( 1513.93 -1.3688 0 0 0 0 0 0 ); // rho = a + bT			
    }
    thermodynamics
    {
        Sf		0;
        Hf              0;
	Tref        	530.59;
        Href        	1122200;
	CpCoeffs<8>     ( 654.38 8.1036 0 0 0 0 0 0 ); // Cp = a + bT
    }
    transport
    {
        muCoeffs<8>     ( 4.053e-4 -5.702e-7 0 0 0 0 0 0 );  // mu = a + bT
	kappaCoeffs<8>  ( 1.0967 -9.1269e-4 0 0 0 0 0 0);  // kappa = a + bT
	Pr          	0.8304;    
    }	
}

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

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  plus                                  |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "constant";
    object      thermophysicalProperties.gas;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

thermoType
{
    type            heRhoThermo;
    mixture         multiComponentMixture;
    transport       const;
    thermo          hRefConst;
    equationOfState rhoConst;
    specie          specie;
    energy          sensibleEnthalpy;
}

dpdt no;

species
(
    water
);

inertSpecie water;

chemistryReader foamChemistryReader;

foamChemistryFile "$FOAM_CASE/constant/reactions.gas";

water
{
    specie
    {
        nMoles          1;
        molWeight       18.0153;
    }
    equationOfState
    {
        R	   1695;	
	rho        22.697;
    }

    thermodynamics
    {
        Hf          0;
        Cp          4227;
        Tref        530.59;
        Href        2797900;
    }
    transport
    {
        mu          1.7777e-5;
        Pr          1.4099;
    }
}

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

[hinmanws]

I am having a similar issue with reactingTwoPhaseEulerFoam.

Were you able to resolve this?

[Sid!]

I am still working on it.

Are you simulating the same case?

[Qinh]

Hello Siddharth,

This thread is almost one year ago. Could you please tell me how did you solve this problem finally? Thank you in advance!

Best regards!
Qinhao

[Sid!]

Hi Qinh,

I managed to solve the problem. Since I was performing an axis-symmetric simulation of flow in a pipe, I had to use the wedge boundary condition. This improved the simulation results.

[Qinh]

Hello Siddharth,

Thank you for your quick reply. By the way, what does the "div\(\(\(\(alpha.*\*thermo:rho.*\)\*nuEff.*)\*dev 2\(T\(grad\(U.*\)\)\)" mean in the fvSchemes in the reactingTwoPhaseEulerFoam? It can not be set as Gauss upwind or Gauss limitedLinear but Gauss linear. I am puzzled about it, could you please give some hints?

Best regards,
Qinhao

[rampal]

Dear friends, I'm doing the same problem in Ansys Fluent. But I am not getting the converged solution. I'm using Eulerian Wall Boiling Model in Fluent. This model giving good results for flow boiling of water in a vertical tube (steady state simulation). Now I am doing for the horizontal tube. First I started with steady state, but the simulation was not converging. Then I switched to transient simulation, but still I'm not getting converged results. Hope you people have solved this problem. Please help me to do this successfully. I'll be thankful to you.

[SHY22]

Originally Posted by Sid!

Hi Qinh,

I managed to solve the problem. Since I was performing an axis-symmetric simulation of flow in a pipe, I had to use the wedge boundary condition. This improved the simulation results.

Hi sid! ,Im using the reactingTwoPhaseEulerFoam to simulate the Bartolomej experiment,and I encountered the same problem as you, I use the wedge boundary but the gas still produces very little, and the parameters in the literature do not match, I want to ask is the example you used in the simulation process is wall boiling? Is this happening because of a setup problem with the phaseproperties file?or thermolphaseproperties? Please give me some advice, thank you very much！！