TY - JOUR A1 - Gugat, Martin A1 - Schultz, RĂ¼diger A1 - Schuster, Michael T1 - Convexity and Starshapedness of Feasible Sets in Stationary Flow Networks T2 - Networks and Heterogeneous Media N2 - We deal with a stationary model for flow through a network. The flows are determined by the values at the boundary nodes of the network that we call the loads of the network. In the applications , the feasible loads must satisfy some box constraints. We analyze the structure of the set of feasible loads. Our analysis is motivated by gas pipeline flows, where the box constraints are pressure bounds. We present sufficient conditions to show, that the feasible set is star-shaped with respect to special points. For stronger conditions, we prove the convexity of the set of feasible loads. All the results are given for active and passive networks, i.e. networks with and without inner control. This analysis is motivated by the aim to use the spheric-radial decomposition for stochastic boundary data in this model. This paper can be used for simplifying the algorithmic use of the spheric-radial decomposition. KW - Validation of nominations, Stationary states, Isothermal Euler equations, Gas networks, Convexity, Star-Shapedness, Spheric-radial decomposition Y1 - 2019 UR - https://opus4.kobv.de/opus4-trr154/frontdoor/index/index/docId/267 SP - 171 EP - 195 ER -