Stephan GersterInstitut für Geometrie und Praktische MathematikRWTH Aachen Templergraben 55 52056 Aachen Germany office: Hauptgegbäude 128.2 phone: +49 241 8094 559 email: (last name)@igpm.rwthaachen.de

Teaching
Mathematik I & II (für Bau, Umwelt, Wirtschafts, Verkehrsingenieurwesen)Research Interests
 Stochastic Galerkin Formulations for Hyperbolic Balance Laws Stochastic Galerkin methods reformulate a stochastic system as a deterministic one that describes the evolution of polynomial chaos modes. So far, results for general hyperbolic systems are not available. A problem is posed by the fact that the deterministic Jacobian of the projected system differs from the random Jacobian of the original system and hence hyperbolicity is not guaranteed. We show for some fluiddynamic equations that hyperbolicity can be guaranteed.
 Feedback Control for Hyperbolic Systems Physical systems such as water and gas networks are usually operated in a state of equilibrium and feedback control is employed to damp small perturbations over time. We consider flow problems on networks, described by hyperbolic balance laws, and analyze their stability.
 Stochastic Fluctuations in Energy Networks The ability of gasfired power plants to ramp quickly is used to balance fluctuations in the power grid caused by renewable energy sources, which in turn leads to timevarying gas consumption and fluctuations in the gas network. Since gas system operators assume nearly constant gas consumption, there is a need to assess the risk of these stochastic fluctuations. We discuss control policies to damp fluctuations in the network.
Publication: Stephan Gerster, Michael Herty, Aleksey Sikstel, Hyperbolic Stochastic Galerkin Formulation for the pSystem, preprint, 2018
Publication: Stephan Gerster, Michael Herty, Discretized Feedback Control for Hyperbolic Balance Laws, preprint, 2017
Conferences and Research Stays
 SIAM Conference on Computational Science and Engineering, Spokane, USA, 2019
 IFIP Conference on System Modelling and Optimization, Essen, Germany 2018
 20th European Conference on Mathematics for Industry, Budapest, Hungary, 2018
 GAMM Annual Meeting, Munich, Germany 2018
 Research stay at Los Alamos National Laboratory, Los Alamos, USA, 2018
 2nd Physics Informed Machine Learning Conference, Santa Fe, USA, 2018
 Conference on Computational Engineering Science, Aachen, Germany, 2017
 Grid Science Winter School and Conference, Santa Fe, USA, 2017