[Achuth]

Hello,

I am working with multiphase flow through a porous medium and I am implementing the temperature equation. I have a doubt regarding how the following convection term needs to be implemented.

(rho*cp) * u * del(T)

How I have implemented it is: rhocf * fvm::div(Uf,T)
where Uf = fvc::interpolate(U) & mesh.Sf();

Is it right? Or should I take the temperature field as a fvc::grad(T) to be precise.

I would really appreciate the help!

[K.C.]

I don't know exactly your meaning of del(T).

I guess you want to implement the advection of your temperature-field, right?
This would mean for constant density and heat capacity your equation reads:

dT/dt = -divergence(u*T) as differential equation.

Most of the time divergence(u) = 0. Therefore you will see dT/dt = -u*gradient(T) most of the time, but the equation above is more generall.

Therfore you need fvc:: (Uf*T_face) for explicit or fvm:: (Uf,T) for implicit discretisation (and fvm::ddt(T)).

I hope this was usefull for you.

[Cyp]

See this presentation pages 84 to 93. See also pages 100 to 108 for a 2 temperatures model.

Cheers,
Cyprien