TY - GEN A1 - Steinbach, Marc T1 - On PDE Solution in Transient Optimization of Gas Networks N2 - Operative planning in gas distribution networks leads to large-scale mixed-integer optimization problems involving a hyperbolic PDE defined on a graph. We consider the NLP obtained under prescribed combinatorial decisions---or as relaxation in a branch and bound framework, addressing in particular the KKT systems arising in primal-dual interior methods. We propose a custom solution algorithm using sparse local projections, based on the KKT systems' structual properties induced by the discretized gas flow equations in combination with the underlying network topology. The numerical efficiency and accuracy of the algorithm are investigated, and detailed computational comparisons with a control space method and with the multifrontal solver MA27 are provided. T3 - ZIB-Report - 04-46 KW - Gas network KW - operative planning KW - PDE constrained optimization KW - KKT system factorization KW - sparse projection method Y1 - 2004 UR - https://opus4.kobv.de/opus4-zib/frontdoor/index/index/docId/821 UR - https://nbn-resolving.org/urn:nbn:de:0297-zib-8215 ER -