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#   This file is part of the project MODAL-EnergyLab in the Research Campus MODAL
#                      funded by the BMBF (05M14ZAM, 05M20ZBM)                   
#                                                                                
# Copyright (C) 2023                                                             
# Zuse Institute Berlin                                                          
# Contact: Thorsten Koch (koch@zib.de)                                           
# All rights reserved.                                                           
#                                                                                
# This work is licensed under the Creative Commons Attribution 3.0 Unported License.
# To view a copy of this license, visit http://creativecommons.org/licenses/by/3.0/ 
# or send a letter to Creative Commons, 444 Castro Street, Suite 900, Mountain View,
# California, 94041, USA.                                                           
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#                         Please note that you have to cite                         
# F. Hennings, "Modeling and solving real-world transient gas network transport     
# problems using mathematical programming",                                         
# Doctoral Thesis, Technische Universität Berlin, 2023                              
#                               if you use this data                                
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The network is a small artificial network that was created to allow for various gas 
routing options despite its size. It consists of 39 nodes and 41 arcs, of which 28 
are pipes, 7 are valves, 4 are control valves, and 2 are compressor stations.

The backbone of the network is a circle of pipes.
It has no principal flow direction but can be used clockwise and counter-clockwise on
every pipe segment. The network features two low-pressure areas with restricted upper 
pressure bounds on the corresponding nodes.
They are located downstream of the four regulators, where the one inside the circle 
can be served from two different network areas. To further enable different flow 
patterns, the boundary nodes are distributed all over the network. The entries are 
located on opposite sides and have slightly lower maximum pressure limits than the 
rest of the nodes.
Furthermore, each of them has a downstream compressor station to potentially increase
the pressure of the gas entering the pipe circle. Regarding the exits, there is one 
close to each of the entries, one in each low-pressure area, and one directly 
connected to the pipe circle. This last exit has a high minimum pressure bound.

For the network, ten stationary demand scenarios with significant mutual differences 
have been created. For a more detailed description of the data and the creation 
process, we refer to the dissertation of Felix Hennings, "Modeling and solving 
real-world transient gas network transport problems using mathematical programming", 2023.