In this condition the normal velocity 
and tangential
stress 
with 
are prescribed. So we don't need
''normal'' velocity half-cells. We have only to consider the two
''tangential'' cells. For the remainder of this section is the slip
boundary condition given on the bottom boundary.
The discretization of the convective terms is given by:
Since 
is prescribed at the bottom boundary we
do not have to use a linear approximation for 
(see [24], formula (3.9)):
The discretization of the stress tensor is given by:
The virtual velocities introduced by formula (7.58) are eliminated
by linear extrapolation, i.e. using formula (7.25),
(7.26) and (7.27).
The term 
in (7.58) is for 
-cell) equal to:
where 
, so:
Term in (7.58) is for 
equal to:
where 
, so:
The factors 
and 
are calculated with formula
(7.24a)-(7.24b).
The 
in (7.60) and (7.62)
involves virtual velocities and pressures that can be eliminated by
(7.25)-(7.27) and (7.48).
Before treating the boundary conditions for the scalar equations we shall
first consider the special cases where we have a transition of one type of
a boundary condition to another as well the case of a corner of the region.
