Flow condition (infiltration)

This boundary condition allows to define an in- or outflow for infiltration boundary problems, by defining the flow velocity \(v\) in m/s on the specific surface. Note that the flow specified via the velocity takes places continuously on the defined surface area, independent of i.e. the pore water pressure \(p^w\).

The volumetric flow rate \(Q\) in m/s\(^3\) is computed via:

\[ Q = v \cdot A, \]

wherein \(A\) in m\(^2\) is the corresponding area of the surface.