CFD Online Discussion Forums - flowRatePatch for multiple patches simultaneously

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flowRatePatch for multiple patches simultaneously

I am trying to process data during run time of an OF model. I can successfully output volume flow rate through a specific patch (say outlet) per instructions here:

https://cfd.direct/openfoam/user-gui...rocessing-cli/

However, I would like to output flow rates for more than one patch, say for both inlet and outlet. Specifically I would like to dump the data like this in two columns:

_________ Inlet______Outlet
time______x.xx_______y.yy

What changes do I need to make to my flowRatePatch file? This is my current one:

HTML Code:

/*--------------------------------*- C++ -*----------------------------------*\

  =========                 |

  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox

   \\    /   O peration     |

    \\  /    A nd           | Web:      www.OpenFOAM.org

     \\/     M anipulation  |

-------------------------------------------------------------------------------

Description

    Calculates the flow rate through a specified patch by summing the flux on

    patch faces.  For solvers where the flux is volumetric, the flow rate is

    volumetric; where flux is mass flux, the flow rate is mass flow rate.



\*---------------------------------------------------------------------------*/



name     outlet;



#includeEtc "caseDicts/postProcessing/flowRate/flowRatePatch.cfg"



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

swak4foam is used to do runtime outputs/calculations/...

You need this in your controlDict

Code:

functions{

massFlow



    {

        type patchMassFlow;

        outputControl timeStep;

        verbose true;

        patches

        (

             inlet

             outlet

        );

        factor 1;

        outputInterval 1;

    }

}

you find more information in here: http://openfoamwiki.net/images/2/2a/...esentation.pdf

in case you only need the finished solution try:
https://www.cfd-online.com/Forums/op...lculation.html

Thanks for your help and suggestion. I tried your method and I got:

HTML Code:

[5] --> FOAM FATAL ERROR: 

[5] Unknown function type patchMassFlow

I am not sure where the patchMassFlow function is residing. BTW I have swak4Foam compiled and working.

I would also prefer to use OF's built-in function of flowRatePatch. Its working perfectly for one defined surface (outlet). I thought that it may be simple to add another surface to the output column.

I tried this in flowRatePatch, but OF didn't like that ether

HTML Code:

name     (inlet outlet);



#includeEtc "caseDicts/postProcessing/flowRate/flowRatePatch.cfg"

If you have swak compiled and working I guess you also have the libs in the controlDict ?

I use

Code:

     "libsimpleSwakFunctionObjects.so"

     "libswakFunctionObjects.so"

Is the type "swakExpression" working for you?
Then you could define your own expression for massFlow, but I believe I cannot help you with rewriting the flowRatePatch function from OF.

flowRatePatch for multiple patches simultaneously

i finally became able of solving this issue.
By writing a bash file it is possible to calculate flow rate patch on different boundaries. Here i leave the linux command:
sed -i "s/name inlet;/name outlet;/g" system/flowRatePatch

Quote:

Originally Posted by CFDelix (Post 676365)

swak4foam is used to do runtime outputs/calculations/...

You need this in your controlDict

Code:

functions{

massFlow



    {

        type patchMassFlow;

        outputControl timeStep;

        verbose true;

        patches

        (

             inlet

             outlet

        );

        factor 1;

        outputInterval 1;

    }

}

you find more information in here: http://openfoamwiki.net/images/2/2a/...esentation.pdf

in case you only need the finished solution try:
https://www.cfd-online.com/Forums/op...lculation.html

Hi Felix,
Seems like OpenFOAM 18 users cannot use swak4foam. I also cannot get flowRatePatch running due to the following warning (simulation continues without patch calculation):

Starting time loop

--> FOAM Warning :
From function bool Foam::functionObjectList::read()
in file db/functionObjects/functionObjectList/functionObjectList.C at line 738
Reading "/home/mm/OpenFOAM/OpenFOAM-v1812/20190509/system/controlDict"
Entry name is not a dictionary

Any thoughts on this are most appreciate :)