Variables and Expressions
The physics interface defines the chemical potential, which can be rewritten in terms of the dependent variable
ψ
,
and the surface tension force
F
=
G
∇
t
ϕ
.
Geometric properties of the interface are often needed. The unit normal to the interface is given by
(11-28)
This variable is available in the physics interface as the interface normal
pftff.intnorm
.
The mean curvature (SI unit: 1/m) of the interface can be computed by entering the following expression:
