[robbedoes]

Hi fellow foamers

First of all, I am still new to OpenFOAM, so hopefully I am not making an obvious mistake here... Any suggestions are much appreciated

I am using reactingFoam (OF v5) to simulate fuel injection in a constant volume chamber filled with air, starting from the DLR_A_LTS tutorial. I set up the boundary conditions similarly to the article of Som (2012), resulting in an initial chamber temperature of 1000 K. As boundary conditions, I used an injection temperature of 373 K at the injector orifice, and a zeroGradient at the walls of the domain. Currently I have no outlet, as I would like to study the interaction of the fuel with the walls. I specified all values in the T file and copied it to T.orig such that both are exactly the same.

Then, when I try to run the simulation, I see that (out of nowhere) the T file is replaced and the value for the initial conditions are replaced with the fuel temperature (so from 1000 K to 373 K)! As a consequence, my entire temperature field in paraview is not what it should be... The weird thing is that the T.orig file is still the same. I checked the Allrun file and took out the line that copies T.orig, but it did not change anything. Does someone have an idea of what's happening here? Also, could someone point out why exactly there exists an .orig file for temperature, but not for p and U for example.

Thanks in advance, and have a nice weekend!
Robbe

P.S.: For clarification, I included both the T files. The first one I made, the second one appeared after the simulation.

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  5                                     |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    location    "0";
    object      T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 1 0 0 0];

internalField   uniform 1000;

boundaryField
{
    injector
    {
        type            fixedValue;
        value           uniform 373;
    }
    walls
    {
        type            zeroGradient;
    }
}


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

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  5.x                                   |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      binary;
    class       volScalarField;
    location    "0";
    object      T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 1 0 0 0];

internalField   uniform 373;

boundaryField
{
    walls
    {
        type            zeroGradient;
    }
}

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

[piu58]

There is a setfields command in the allrun file. Check that.

[robbedoes]

Originally Posted by piu58

There is a setfields command in the allrun file. Check that.

Hi Uwe

Thanks for your answer. That did the trick!

Could you (or someone else) please elaborate a bit on the meaning of the setFieldsDict file? If I understand correctly, I have already set the initial value of the field in the T file, so why exactly do I need to specify it again? Also, why don't the pressure and velocity need such an additional entry in setFieldsDict?

Thanks again.

Robbe

[piu58]

Setfileds is not necessary in closer sense. You may always set the filed in the 0/T file in your example.
Setfields hels to set a filed independend from te mesh. If you use a finer mesh, simply by changing some hex commands, a

value nonuniform List<scalar>

command needs to be changed. With setfields you may avoid this.