5.3 Interfaces

To account for complex interface conditions, variables on grid points located at interfaces (see Fig. 5.1a) are allowed to have two values, one for each segment (see Fig. 5.1b) to account for abrupt changes at interfaces. In the following these interface points will be given as i and i'. The constitutive relations for both points are incomplete since in the segment models only the flux terms to points of the same segment are considered. Furthermore, an additional equation is required for this additional variable at the interface. Depending on the interface type two cases must be considered:

Figure 5.1: Splitting of interface points: Interface points as given in a) are split into two different points having the same geometrical coordinates b)