[maysan]

Hello,

Is it possible to use the runTimeControl functionObject as shown in https://www.openfoam.com/documentati...e-control.html for the total force in the z-direction instead of the Drag Coefficient?

If so, how can I do it?
I tried to replace Cd with total_z but the output is:

runTimeControl runTimeControl1 output:
    runTimeControl: condition0 averages:
--> FOAM Warning :
    From virtual bool Foam::functionObjects::valueAverageBase::calculate(Foam::dictionary&)
    in file db/functionObjects/valueAverageBase/valueAverageBase.C at line 218
    From function object: forces1
Unprocessed fields:
            total_z

Can this be fixed?

[Yann]

Hello,

Did you define a force function object to computes forces beforehand?
How is your runTimeControl function defined?

[maysan]

Originally Posted by Yann

Hello,

Did you define a force function object to computes forces beforehand?
How is your runTimeControl function defined?

Hi,
Like this:

functions
{
    forces1
    {
        type            forces;
        libs            (forces);
        patches         (patch1);
        rhoInf          1000;
        log             on;
        writeControl    timeStep;
        writeInterval   1;
        CofR            (0 0 1);
    }

    runTimeControl1
    {
        type            runTimeControl;
        libs            ("libutilityFunctionObjects.so");
        conditions
        {
            condition0
            {
                type            average;
                functionObject  forces1;
                fields          (total_z);
                tolerance       1e-3;
                window          10;
                groupID         1;
                windowType      approximate;
            }
        }
    }
}

[Yann]

Alright so it seems the question is: what are the proper names of the fields returned by the forces function object. You can find it if you look into a saved time directory in uniform/functionObjects/functionObjectProperties

It seems the forces function returns the following values:

• pressureForce
• viscousForce
• internalForce
• pressureMoment
• viscousMoment
• internalMoment

You can use one of those fields in your runTimeControl function but all are vectors, so I don't know how the runtimeControl function handles it (like, does it process the vector magnitude?)
And I don't know if there is a way to only use one of the vector component.

Not really an answer to your question, but I hope it gives some insights.
Yann