[überschwupper]

Dear Foamers,


I cannot wrap my mind around this problem. I have initialised a dimensionedScalar(dimMass/dimTime, 0) and then I want to integrate over all cells if a condition is met. But everytime the loop starts or is running through all cells at some point a conflict with not matching dimensions occurs.


The code looks like this:

dimensionedScalar intPhiVap("intPhiVap", dimMass/dimTime, 0);


forAll(mesh_.C(), celli)
{
    if (alpha1()[celli] < alphaCutOff_)
    {
        intPhiVap.value() += (1.0-alpha1()[celli])*phi[celli]*mesh_.V();

    }

}

Unfortunately this snippet returns an error at some time (lets say whenn celli=1000), that dimensions are different

dimensions [0 0 0 0 0 0 0] = [1 0 -1 0 0 0 0]
From function bool Foam::dimensionSet::operator=(const Foam::dimensionSet&) const

Since the above equation has no assignment operator (and I expect this is a check done by dimensioned<Type> Class)I checked which dimensions intPhiVap.value() has and it has no dimensions and is of type scalar/double. Since phi*mesh.V() is kg/s I thought about changing this line to

intPhiVap += (1.0-alpha1()[celli])*phi[celli]*mesh_.V();

But this results into following error directly after the if condition (so at the first iteration step)

Different dimensions for +=      dimensions : [1 0 -1 0 0 0 0] = [0 0 0 0 0 0 0]       

From function bool Foam::dimensionSet::operator+=(const Foam::dimensionSet&) const

Thats why I wanted to avoid the += operator and I changed the line to

intPhiVap = (1.0-alpha1()[celli])*phi[celli]*mesh_.V() + intPhiVap;

But this was followed by another error

--> FOAM FATAL ERROR: 
LHS and RHS of + have different dimensions
     dimensions : [0 0 0 0 0 0 0] + [1 0 -1 0 0 0 0]


    From function Foam::dimensionSet Foam::operator+(const Foam::dimensionSet&, const Foam::dimensionSet&)

Which is strange, because the product results in the dimensions of kg/s and so does intPhiVap. So I tried

intPhiVap = (1.0-alpha1()[celli])*phi[celli]*mesh_.V() + intPhiVap.value();

As expected this results into following error:

--> FOAM FATAL ERROR: 
Different dimensions for =
     dimensions : [1 0 -1 0 0 0 0] = [0 0 0 0 0 0 0]


     From function bool Foam::dimensionSet::operator=(const Foam::dimensionSet&) const

Next try was:

intPhiVap.value() = (1.0-alpha1()[celli])*phi[celli]*mesh_.V() + intPhiVap.value();

The result was, that the for loop was running further and has not interrupted directly at first step, but the error message was then:

--> FOAM FATAL ERROR: 
Different dimensions for =
     dimensions : [0 0 0 0 0 0 0] = [1 0 -1 0 0 0 0]


     From function bool Foam::dimensionSet::operator=(const Foam::dimensionSet&) const

I dont understand why nothing of above is working. It feels so arbitrary. I mean the product of the RHS should always has the dimensions kg/s and so should the LHS. But it seems, that the for-loop allows exceptions to this. I expect, that the issue arises, when the product is 0 for the dimension mismatch on the LHS and when the product is not 0 then on the RHS, but I have no clue. But how should it be possible? iterating through a field should always return the same dimensions, no matter what value is saved in that space..


I really hope someone has an idea how tofix this. Thank you all in advance

[überschwupper]

I'm not sure if the upper problem is solved but it seems like I have found a work around specificly for my work.


The above code snippet was inside a function that should return a Pair<dimensionedScalar>, but asap the single values are written, dimension mismatch is occuring.

Pair<dimensionedScalar> calcPhis()
//Code
return Pair<dimensionedScalar>
(
    intPhiLiq,
    intPhiVap
);


Pair intPhis(calcPhis);

nevertheless, i dont have a clue, why this rises an error of dimension mismatch..