[nellosamr]

Dear all,
I've a problem with the implementation of an equation caused by incompatibility between different classes.
I've to calculate a coefficient which is function of the magnitude of a geometric field vector (E). The resolution dependes from a comparison with a reference value, as shown down.

4.71x10^(-11)*|E/p|^3        for |E/p|<referenceValue
3.32(|E/p|-12500)^0.5        for |E/p|>referenceValue
referenceValue=1.4x10^4

My problem is that I can't compare the |E/p| with a reference value. I've tryed to give the reference value as a volScalarField, but it results that the ">" can be used only with scalars, I've tryed to write also max(mag(E/p),mag(referenceValue))operator==mag(referenceValu e), but it seems that this instruction work only with bool. Also (mag(electricField/p).)value() doesn't work.
I don't know how to proceed.
Thank you in advance for your help.
Best Regards,
Antonio

[ankur_garg]

Hi nellosamr,


First, I want to understand your problem clearly. The Coefficient which you want to calculate is Scalar? And Geometric Field vector is a vector quantity? And what is p here?


Thank you very much.

Regards,
Ankur

[Pedro24]

Hi nellosamr,

If referenceValue is a scalar, you can do a loop over the cell like that :

forAll(mesh.C(),celli)
{
if ((E[celli]/p[celli]) < referenceValue)
{
newField[celli] = something(E[celli]/p[celli];
}
else
{
// do 2
}
}

you sould make the same over the patches if necessary.

Sincerely,

Pierre

[nellosamr]

Thank you both in advance for your answer.

Originally Posted by ankur_garg

Hi nellosamr,


First, I want to understand your problem clearly. The Coefficient which you want to calculate is Scalar? And Geometric Field vector is a vector quantity? And what is p here?


Thank you very much.

Regards,
Ankur

The coefficient is a dimensionedScalar. The geometricField E is a vector quantity, while the pressure p is a volScalarField.

Originally Posted by Pedro24

Hi nellosamr,

If referenceValue is a scalar, you can do a loop over the cell like that :

forAll(mesh.C(),celli)
{
if ((E[celli]/p[celli]) < referenceValue)
{
newField[celli] = something(E[celli]/p[celli];
}
else
{
// do 2
}
}

you sould make the same over the patches if necessary.

Sincerely,

Pierre

Ok, I've tried it and it compiles. Now, I've to fix some other features, and then I will try to launch the solver on a well-known test case.
Thank you again for your attention and courtesy.
Best regards,
Antonio