Use the Hydraulic Head node to specify the hydraulic head (instead of the pressure) on a boundary. This adds the Dirichlet condition for the hydraulic head
H = H0 where
H0 is a known hydraulic head given as a number, a distribution, or an expression involving time,
t, for example.
Enter a value or expression for the Hydraulic head H0 (SI unit: m). The default is 0 m.
) and select Advanced Physics Options in the Show More Options dialog box.