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.

The Subsurface Flow Module license is required to use this boundary condition (see http://www.comsol.com/products/specifications/).

Enter a value or expression for the Hydraulic head H0 (SI unit: m). The default is 0 m.

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