Volume Discrepancy Factor
The volume discrepancy term is used in the constraint equation to force the system back to the equation of state. We write our velocity constraint equation as
Here,
The idea behind this forcing term is that if
In MAESTROeX, we decomponse the velocity into a base state component
and a local component. The base state constraint equation is simply
the horizontal average of the full constraint. Starting with
Averaging this over a layer, we note that
and
In solving the
Recalling that
(see Paper I), and that
This is the form that is solved in make_w0
.