From 5cfd24af775270bc97533ba7a6201b248e528bb2 Mon Sep 17 00:00:00 2001
From: Utz <utzm@w5pc123.all.baw.de>
Date: Wed, 28 Nov 2018 12:05:56 +0100
Subject: [PATCH] Add the first draft of parrallel section
The new content is included, but the formulation has to be improved.
---
doc/handbook/0_dumux-handbook.tex | 1 +
doc/handbook/5_parallel.tex | 59 +++++++++++++++++++++++++++++++
2 files changed, 60 insertions(+)
create mode 100644 doc/handbook/5_parallel.tex
diff --git a/doc/handbook/0_dumux-handbook.tex b/doc/handbook/0_dumux-handbook.tex
index e0b7626449..73b349e6f0 100644
--- a/doc/handbook/0_dumux-handbook.tex
+++ b/doc/handbook/0_dumux-handbook.tex
@@ -148,6 +148,7 @@ in deeper modifications of underlying \Dumux models, classes, functions, etc.
\input{5_stepsofasimulation}
\input{5_propertysystem}
\input{5_grids}
+\input{5_parallel}
\bibliographystyle{plainnat}
\bibliography{dumux-handbook}
diff --git a/doc/handbook/5_parallel.tex b/doc/handbook/5_parallel.tex
new file mode 100644
index 0000000000..6583774e38
--- /dev/null
+++ b/doc/handbook/5_parallel.tex
@@ -0,0 +1,59 @@
+\section{Parallel Computation}
+\label{sec:parallelcomputation}
+
+\Dumux also support parallel computation. The parallel version needs an external MPI libary.
+
+Posibilities are OpenMPI MPICH and IntelMPI.
+
+Depending on the grid manager METIS or ParMETIS can also be used for paritioning.
+
+
+In the following show how to prepare a model an run it in parallel whith
+the imcompressible 2p model.
+
+dumux/test/porousmediumflow/2p/implicit/incompressible
+
+
+\subsection{prepareing the model}
+
+If the parallel AMGBackend is not allready set in your application
+you should from the sequential solver backend to the parallel amg backend
+in your application.
+
+First include the header files for the parallel AMGBackend
+#include <dumux/linear/amgbackend.hh>
+
+and remove the header files of the sequential backend
+
+#include <dumux/linear/seqsolverbackend.hh>
+
+
+Second, hange the linear solver to the AMG solver
+from the AMGBackend
+
+using LinearSolver = Dumux::AMGBackend<TypeTag>;
+
+and recompile your application.
+
+\subsection{Start parallel computation}
+The parallel simulation is starte with mpirun followed by -np and
+the number of cores that should be used and the executable.
+
+mpirun -np n_cores executable
+
+On HPC cluster you usually have to use qeuing system like (e.g. slurm).
+
+
+
+\subsection{Handling Parallel Results}
+The results sould not differ between parallel an serial execution. As in
+the serial case you get vtu-files as output. However you have an additional
+variable "process rank" that shows the processor rank of each MPI partition.
+
+
+
+
+
+
+
+
--
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