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MRF-Boundary Condition U and equivalent for SRF Urel

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Old   March 4, 2024, 15:09
Smile MRF-Boundary Condition U and equivalent for SRF Urel
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Daniel
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Hei,

i have a hard time bc I have to do a MRF and a SRF Simulation of a pump turbine- in my MRF my U look like this:

Code:
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2012                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volVectorField;
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField   uniform (0 0 0);

boundaryField
{
    IF_LAUF_LEIT
    {
	type            cylindricalInletVelocity;
        axis            (0 0 1);
        origin          (0 0 0);
        axialVelocity   constant 0;
        radialVelocity  constant -10;
        rpm             constant 800;;
        value           uniform (0 0 0);    
    }

    IF_LAUF_SAUGROHR
    {
	type            zeroGradient;
    }

    "(cP_cyclicA|cP_cyclicB)"
    {
        type            cyclic;
    }

    "(NABE|KRANZ|SCHAUFEL)"
    {
        type            fixedValue;
	value		uniform (0 0 0); //Wenn hier alle 3 Null stehen dann dreht es sich mit omega
	
    }
}

// ************************************************************************* //
the simulation looks goof to me. But I don't understand what the radial component exactly is. is the 10 m/s a velocity in Cartesian or cylindrical components? I think in cylindrical bc you have to define axial and radialvelocity. How can I understand the 10 m/s in radial direction? is this an absolut velocity or a relativ?

how can I find the equivalent for Urel for the SRF simulation.

I found this in on of the tutorials

Code:
dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (0 0 0);

boundaryField
{
    IF_LAUF_LEIT
    {
        type            SRFVelocity;
	inletValue      uniform (-10 0 0);
	relative        no;
	value		uniform (0 0 0);
    }
everything else stays the same as in the MRF.

what exactly is the inlet value? and do I need to put relativ yes or no?

To compare both simulation I need equal BC... But I don't understand if the SRFVelocity Vektor is in cartesian coordinates or also in cylindrical like the BC at the MRF ?

Can someone help me please...
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