Hello,
First of all, thank you for your previous answers, it was very helpful
and quite hit the mark.
Now, I'm still struggling with the concept of Face/CellVariable. What
confuses me is the use of CellVariables in diffusion or convection terms.
For example in the module examples.diffusion.mesh1D on page 67, phi,
which is a CellVariable, is used in the coefficient of the
ImplicitDiffusionTerm. Is this one of those cases where "FiPy will
automatically substitute var.getArithmeticFaceValue()" as mentionned in
the FAQs?
If so, how would it be possible to be more rigorous and "explicitly
supply the desired FaceVariable rather than letting FiPy assume one"? In
other words, how is it possible to explicitly supply a FaceVariable when
this variable is already declared as a CellVariable?
It is important to me because I encounter this situation in the system
of equations I would like to solve:
\[
\frac{\partial}{\partial t}(c y_F) + \nabla \cdot (c \vec{v} y_F) =
\nabla \cdot (c \bar{D} \nabla y_F)
\]
\[
\frac{\partial}{\partial t}(c y_F \theta) + \nabla \cdot (c \vec{v} y_F
\theta) =
\nabla \cdot (c \tilde{D} \nabla y_F \theta)
\]
\[
\frac{\partial}{\partial t}(c y_F \Psi) + \nabla \cdot (c \vec{v} y_F
\Psi) =
\nabla \cdot (c \hat{D} \nabla y_F \Psi)
\]
The variables I'm solving for are yF, theta and Psi.
Many thanks,
Etienne Rivard, MSc
Mitarbeiter
Lehrstuhl für Technische Thermodynamik und Transportprozesse (LTTT)
Universität Bayreuth
Universitätsstr. 30
95440 Bayreuth
Deutschland
