[flux]

Hi,

i am trying , to probe the magnitude of the U-field at a specific position.

I have already tried the following code in my controldict, but i always get the U-field in components or nothing:

  
functions {
    probes
    {
        type            probes;
        functionObjectLibs     ("libsampling.so");
        enabled                 true;
        outputControl        timeStep;
        outputInterval       1;
        probeLocations
        (
            (-0.2 -0.05 0)
        );

        fields
        (
        U
        magU
        mag(U)
        );
    }
}

So what should i do, to get an x-y list of the itaration step and the magnitude of the U field?


Thanks!

[tomf]

Hi,

I am not sure if it can be done within the controldict, but this command on the terminal will give you the magnitude of U for each probed timestep:

sed 's/(/ /g' postProcessing/probes/0/U | sed 's/)/ /g' | awk '{print $1 " " sqrt($2*$2+$3*$3+$4*$4)}' >  postProcessing/probes/0/magU

Regards,
Tom

[flux]

thx, but i calculated the magnitude with excel^^

[Bernhard]

Originally Posted by tomf

Hi,

I am not sure if it can be done within the controldict, but this command on the terminal will give you the magnitude of U for each probed timestep:

sed 's/(/ /g' postProcessing/probes/0/U | sed 's/)/ /g' | awk '{print $1 " " sqrt($2*$2+$3*$3+$4*$4)}' >  postProcessing/probes/0/magU

Regards,
Tom

Your sed commands can be replaced by

tr "()" " "

[Harald]

Hello,

today I faced the same challenge as you did a few years ago. After some elaboration, I managed to calculate the mag(U)-probes directly with OpenFOAM-8.

To do the same, you have to:

1) include the mag(U)-function in controlDict

functions
{
  #includeFunc  mag(U);
}

2) get the probes-dictonary (in case you have not got it yet)

foamGet probes

3) define your probe locations in system/probes and add mag(U) to the list

fields (p U mag(U));
probeLocations
(
    (0 0 0)
);

4) calculate mag(U)

postProcess -func "mag(U)"

and finally

5) get the probes

postProcess -func probes

In a script, you could also combine (4) and (5) as follows:

for x in mag\(U\) probes
do
runApplication -append postProcess -func "${x}"
done

For steady-state solvers, you may want to add an additionally latestTime-flag to the above commands.


Kind regards,
Harald