In \Dumux two sorts of models are implemented: Fully coupled models, and decoupled models. In the fully coupled models a flow system is described by a system of strongly coupled equations which can be mass balance equations, balance equations of components, energy balance equations, etc. In contrast a decoupled model consists of a pressure equation which is decoupled or only weakly coupled to a saturation equation, concentration equations, energy balance equations, etc.
Different kinds of both coupled and decoupled models can be isothermal two phase models, isothemal two phase two component models, non-isothermal twophase model, non-isothermal two phase two component models, etc.
The following two sections of the tutorial demonstrate how to solve problems first using a coupled model (section \ref{tutorial-coupled}) and second using a decoupled model (section \ref{tutorial-decoupled}). Being the easiest case, a isothermal two phase system (two fluid phases, one solid phase) will be considered.
