[waku2005]

Hi all,

I try to modify "rotatingMotion.C/H" of solidBodyMotionFunctions as those can calculate moment vector from p(pressure) and U(viscousity).
Thus, I hope to obtain p and U from previous timestep results.
I'd like to know the way to access such results if available.

Another question. rotatingMotion class has a constructer as below.
It uses runTime as time_, and runTime　is a objectRegistory.
I can access to p and U via runTime(i.e.,time_) ?

Thanks in advance,
waku2005

        //- Construct from components
        rotatingMotion
        (
            const dictionary& SBMFCoeffs,
            const Time& runTime
        );

        //- Construct and return a clone
        virtual autoPtr<solidBodyMotionFunction> clone() const
        {
            return autoPtr<solidBodyMotionFunction>
            (
                new rotatingMotion
                (
                    SBMFCoeffs_,
                    time_
                )
            );
        }

[nimasam]

you can use following structure to read U or p from solver:

const volVectorField& U = db().lookupObject<volVectorField>("U");

[waku2005]

Hi, nimasam

Thank you for your reply.

I added "#include "volFields.H"" and the line you mentioned.

#include "DDrotatingMotion.H"
#include "addToRunTimeSelectionTable.H"
#include "mathematicalConstants.H"

#include "volFields.H"  //<-- added

// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //

Foam::septernion
Foam::directDrivenMotionFunctions::DDrotatingMotion::transformation() const
{
    scalar t = time_.value();

    // Rotation around axis
    scalar angle = omega_->integrate(0, t);

    const volVectorField& U = db().lookupObject<volVectorField>("U");  //<-- added
    
    quaternion R(axis_, angle);
    septernion TR(septernion(-origin_)*R*septernion(origin_));

    DebugInFunction << "Time = " << t << " transformation: " << TR << endl;

    return TR;
}

Unfortunately build was failed as bellow:

directDrivenMotionFunctions/DDrotatingMotion/DDrotatingMotion.C: In member function ‘virtual Foam::septernion Foam::directDrivenMotionFunctions::DDrotatingMotion::transformation() const’:
directDrivenMotionFunctions/DDrotatingMotion/DDrotatingMotion.C:82:34: error: ‘db’ was not declared in this scope
     const volVectorField& U = db().lookupObject<volVectorField>("U");
                                  ^
directDrivenMotionFunctions/DDrotatingMotion/DDrotatingMotion.C:82:63: error: expected primary-expression before ‘>’ token
     const volVectorField& U = db().lookupObject<volVectorField>("U");

# DDrotatingMotion.C (and .H) is my own function file but they are still the same with the original rotaitngMotion.C (and .H).

How do I access to db() ?

Best regards
waku2005

[waku2005]

Hi

I changed the line to:

    const volVectorField& U = time_.db().lookupObject<volVectorField>("U");

and the build was in success, but failed with runtime error as bellow:

--> FOAM FATAL ERROR: 

    request for volVectorField U from objectRegistry mixerVesselAMI2D failed
    available objects of type volVectorField are
0()

db() has no registerdObject ?

waku2005

[Neka]

Hi waku2005,

I'm struggling with a similar Problem.

I have to define an additional function in the class multiComponentMixture and for this new function I need to access the volScalarField rho at each time step.

Did you succeed to resolve this issue?

Best regards
Neka

[Neka]

Here is one possibility:

Accessing fields calculated in a solver within a class