Commit 2cef4817 authored by Beatrix Becker's avatar Beatrix Becker
Browse files

[handbook] new structure, add TODOs

parent 88b9cebd
......@@ -122,29 +122,20 @@ $\boldsymbol{v}_\alpha$ & velocity (Darcy or free flow)& & \\
\label{fig:phaseMassEnergyTransfer}
\end{figure}
\subsection{Available Models}
We distinguish fully-implicit and sequential models. A list of all available models can be found
A list of all available models can be found
in the Doxygen documentation at
\url{http://www.dumux.org/doxygen-stable/html-\DumuxVersion/modules.php}.
The documentation includes a detailed description for every model.
\subsubsection{Fully-Implicit Models}
The fully-implicit models are using the box or the
cell-centered finite volume method as described in section \ref{box} and \ref{cc}
for spatial and the implicit Euler
method as temporal discretization. The fully-implicit models are located in
subdirectories of \texttt{dumux/freeflow}, \texttt{dumux/geomechanics},
and \texttt{dumux/porousmediumflow}.
\subsubsection{Temporal discretization}
We discretize time with an explicit or implicit Euler
method.
% TODO: make section with more details on temporal discretization
Grid adaption is available for both discretization schemes, box and cc. The \texttt{adaptionhelper}-method has to be adjusted to the respective model.
Note that the current implementation only ensures mass conservation for incompressible fluids.
In general, the spatial parameters, especially the porosity, have to be assigned on
the coarsest level of discretization.
\subsubsection{Sequential Models}
The basic idea of the sequential models is to reformulate the
\subsubsection{Algorithms to solve equations}
The governing equations of each model can be solved monolithically or sequentially.
The basic idea of the sequential algorithm is to reformulate the
equations of multi-phase flow into one equation for
pressure and equations for phase/component/... transport. The pressure equation
is the sum of the mass balance equations and thus considers the total flow of the
......@@ -152,12 +143,9 @@ fluid system. The new set of equations is considered as decoupled (or weakly cou
and can thus be solved sequentially. The most popular sequential model is the
fractional flow formulation for two-phase flow which is usually implemented applying
an IMplicit Pressure Explicit Saturation algorithm (IMPES).
In comparison to a fully implicit model, the sequential structure allows the use of
In comparison to solving the equations monolothically, the sequential structure allows the use of
different discretization methods for the different equations. The standard method
used in the sequential models is a cell-centered finite volume method. Further schemes,
used in the sequential algorithm is a cell-centered finite volume method. Further schemes,
so far only available for the two-phase pressure equation, are cell-centered finite
volumes with multi-point flux approximation (MPFA O-method) and mimetic finite differences.
An $h$-adaptive implementation of both sequential models is provided for two dimensions.
The sequential models are located in
subdirectories of \texttt{dumux/porousmediumflow}.
An $h$-adaptive implementation of both sequential algorithms is provided for two dimensions.
\section{Spatial Discretization Schemes}
\label{spatialdiscretization}
For the implicit models there are two spatial discretization schemes (box and Cell
Centered Finite Volume Method) available which are shortly introduced
in this subsection.
We discretize space with the cell-centered finite volume method (\ref{box} ), the box method (\ref{cc})
or a staggered grid scheme.
Grid adaption is available for both box and cell-centered finite volume method.
Note that the current implementation only ensures mass conservation for incompressible fluids.
In general, the spatial parameters, especially the porosity, have to be assigned on
the coarsest level of discretization.
\subsection{Box Method -- A Short Introduction}\label{box}
......@@ -199,3 +202,11 @@ should only be applied for structured grids
direction of the gradient between the two element/control
volume centers).
% \subsubsection{MPFA}\label{staggered}
% TODO
% \subsubsection{NLTPFA}\label{staggered}
% TODO
% \subsection{Staggered Grid -- A Short Introduction}\label{staggered}
% TODO
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