CFD Online Discussion Forums - regionCouple in multiRegionFoam

hi,

this is regarding a combination of the regionCouple BC and the chtMultiRegionFoam solver.
I am working on a new solver for mhd-application starting from the chtMultiregionFoam with its fields setup like

Code:

UFluid.set

            (

                    i,

                    new volVectorField

                    (

                        IOobject

                        (

                                "U",

                                runTime.timeName(),

                                fluidRegions[i],

                                IOobject::MUST_READ,

                                IOobject::AUTO_WRITE

                        ),

                        fluidRegions[i]

                     )

            );

so for the relevant variables (e.g. U) there are sets (the regions) and i end up with as many sets for the variables as i have regions... which is totally fine so far.
Typically you have scalar values like T passing from one region to the other while there is a need of BC to treat the "passing" (e.g. solidWallMixedTemperatureCoupled) which are also working in my case for the electricPotential (see the other posts here in the forum).
But how is it about vectorial values (like the electric Field j)?
At the "internal" BC for this values i need to specify smth. but actually one just wants the neighbor values being recognized. A zeroGradient isn´t working for absolutely logical reasons because even if the simulation is running nicely and converging... the regions aren´t interacting over the internalBC... let´s say they don´t see each other they are just zeroGradient. So this is half the way wrong...the Gradient needs to know about the value on "the other side".

So.
If i look at regionCouple: this is exactly what we need, the values are connected.
And here´s the kicker: how can i initialize my fields like i do in chtMultiRegionFoam (one after another because of

Code:

forAll(fluidRegions, i)

    {..

}..

forAll(solidRegions, i)

    {...

}

) while the regionCouple wants to have the corresponding value for the shadowPatch at the same time??

Code:

Adding field J 







--> FOAM FATAL ERROR: 



    request for volScalarField Elpot from objectRegistry SOLID failed

    available objects of type volScalarField are



0

(

)

Combining multiple Regions like this is like a 1:1 GGI...
Hope you can get my point.
Looking forward for some thoughts on that.

Tanks in advance,

neewbie