[Sören Sander]

Hello Foamers,

usually, a dictionary (e.g. the physicalProperties or transportProperties inside the case file) is read by adding

IOdictionary physicalProperties
(
    IOobject
    (
        "physicalProperties",
        runTime.constant(),
        mesh,
        IOobject::MUST_READ_IF_MODIFIED,
        IOobject::NO_WRITE
    )
);

Adding this line into intermediate/parcels/Templates/KinematicParcel/KinematicParcel.C

template<class ParcelType>
template<class TrackData>
void Foam::KinematicParcel<ParcelType>::calc
(
    TrackData& td,
    const scalar dt,
    const label cellI
)
{
    // Define local properties at beginning of time step
    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    IOdictionary myDict_
    (
        IOobject
        (
            "myProperties",
            runTime.constant(),
            mesh,
            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );

gives the error

lnInclude/KinematicParcel.C: In member function 'void Foam::KinematicParcel<ParcelType>::calc(TrackData&, Foam::scalar, Foam::label)':
lnInclude/KinematicParcel.C:122:13: error: 'runTime' was not declared in this scope
             runTime.constant(),
             ^
lnInclude/KinematicParcel.C:123:13: error: 'mesh' was not declared in this scope
             mesh,
             ^

In the main solver " #include "createTime.H" " creates runTime, if I am not mistaken. However, I need to access a variable amount of aPriori defined values inside the kinematic parcel.
How to access this values inside the KinematicParcel class?
Can I access runTime inside the KinematicCloud/KinematicParcel class or am I going a wrong way here?
I saw that the class definition of KinematicParcel.H has

template<class ParcelType>
class KinematicParcel
:
    public ParcelType
{
public:

    //- Class to hold kinematic particle constant properties
    class constantProperties
    {
...

However, I was not able to add a variable here.

Any ideas are welcome,
Best regards,
Sören

[Tobi]

Dear Sören,

you have a knot in your mind. The solver is not related to the library therefore it tells you that you have no variable named runTime in the lib that you trying to modify. The first thing, never call of a dict in a calc function. Do it within the constructor and save the dictionary as a member variable (but that is up to you).

For example. In the constructor you would have fields like U_ that can be used to get the time. If I am not wrong its like U_.mesh().time(); In your case you only have 3 variables:

TrackData& td,
const scalar dt,
const label cellI

You are trying to build a IOobject that can be done like that:

 IOobject (const word &name, const fileName &instance, const objectRegistry &registry, readOption r=NO_READ, writeOption w=NO_WRITE, bool registerObject=true)

As you see, the the second argument is a file name and the third one an objectRegistry. Now the question is how to get these. In the header file there is nothing related to these object. So if it is possible you can have access to already available registry fields with ->db() or you can extract anything from the TrackData field. A short look into doxygen shows that trackData is only a List<>. So not related to any registryObject file.

Hence I would prefer to do it in the constructor and save this dictionary as a member of your class. Then you have access to it.

[Sören Sander]

Hi Tobi,

thank you very much for "unknoting" me there. Your suggestion works fine, even though I have the vague feeling OpenFOAM handles this slightly different from my solution (I pass the dict like the fields are passed, it seems OF does read the dict inside the constructor, however I had some issues doing the same there).

Best regards,
Sören

[Tobi]

Hi,

as I am a Bavarian I understand your phrase "unknoting" but I am not sure if we are allowed to translate it directly

Anyway... where is the problem? If I understand it correctly, you added a argument to the constructor and read the file there or you want to add the argument to the function?

I am happy that I could help you.

[Sören Sander]

Fields are read as an argument of the constructor, e.g.

    Info<< "Constructing kinematicCloud " << kinematicCloudName << endl;
    basicKinematicCollidingCloud kinematicCloud
    (
        kinematicCloudName,
        rhoInf,
        U,
        ...

which means, I need to construct them at the main solver first and then pass them towards the particle library. Using db() functionality, I could also access the values inside the calculator function (which would result in re-reading the values quite too often, as you already pointed out).
However, OpenFoam seems to create dictionaries in libraries inside the constructor, without passing them, e.g.

        //- Thermo parcel constant properties
        typename parcelType::constantProperties constProps_;

This way the constructor does not need the dictionary as an input argument. I guess one would need to add a new dictionary somewhere there? What I tried:

1. Add it directly to the loop inside the :

   
   //Read from dictionary named "myProperties"
    IOdictionary myProperties
    (
        IOobject
        (
            "myProperties",
            td.cloud().U().time().constant(),
            td.cloud().U().db(),
            IOobject::MUST_READ_IF_MODIFIED,
            IOobject::NO_WRITE
        )
    );
    Foam::dimensionedScalar myValue = myProperties.lookup("myValue");

Which works inside the "calc" routine. But adding it to the constructor lead to an error as "td" is unknown (not defined there). I guess I miss how to access the fields inside the constructor.