### One-dimensional transport element

The discrete form of the differential equation for mass transport for a one-dimensional transport element is

 (269)

where is a vector containing the nodal values of the capillary pressure, is the conductivity matrix, is the capacity matrix and is the nodal flow rate vector ().

The capacity matrix is

 (270)

where is the capacity of the material, l is the length of the transport element and is the cross-sectional area of the transport element.

The conductivity matrix is defined as

 (271)

Borek Patzak
2018-01-02