In the previous five steps all corrections to the conservative variables have
been determined. Now in subroutine updatecfd.f, these corrections, which were stored in field v, are
added to the conservative variables at the start of the increment (stored in
field voldaux). The sum is saved again in voldaux, i.e. this field is
updated. Subsequently, the physical variables temperature and velocity are
determined and stored in field vold(0..3,*). Furthermore, for gases the pressure is
calculated and stored in vold(4,*). The norm of the conservative variables and
their increments is calculated and stored for later use in the convergence
check.