[andrea5]

Hello,

I follow this forum basically everyday, and usually I am able to find all the answers that I am lookig for, but in this case I tried, but I dind't find anything, so first of all sorry if the question has already been made.


My problem is really easy, I am dealing with a steady scalar advection-diffusion equation, but in this case the velocity field is not a vector field, but is just a scalar, let's say equal to 5.

I have noticed that the ScalarTransportFoam and in general when this equation is implemented, it's common to solve it as follows:

solve
(
+ fvm::div(phi, T) // Convective term
- fvm::laplacian(DT, T) // Diffusive term
);


my main problem consists in the fact that the term "phi" cannot be evaluated, since I don't have a vector field, that's why, when I implement it, I don't exactly know how to express all the terms, I have to implement the following statement:


k*grad(T) - DT*(laplacian(T)

where both K and DT are just constant real number.


If I try something like:


(
fvc::grad(T)*k
- fvm::laplacian(c,T)
);



he gives me problems, because of course it's inconsistent.


both k and DT are defined as just dimensionedScalar in the transportProperties dict.



thanks to everyone for your time and help!


Andrea.