Conference article

Numerical coupling of Modelica and CFD for building energy supply systems

Manuel Ljubijankic
Universität der Künste Berlin, Lehrstuhl für Versorgungsplanung und Versorgungstechnik, Germany

Christop Nytsch-Geusen
Universität der Künste Berlin, Lehrstuhl für Versorgungsplanung und Versorgungstechnik, Germany

Jörg Rädler
Universität der Künste Berlin, Lehrstuhl für Versorgungsplanung und Versorgungstechnik, Germany

Martin Löffler
TLK-Thermo GmbH, Germany

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Published in: Proceedings of the 8th International Modelica Conference; March 20th-22nd; Technical Univeristy; Dresden; Germany

Linköping Electronic Conference Proceedings 63:32, p. 286-294

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Published: 2011-06-30

ISBN: 978-91-7393-096-3

ISSN: 1650-3686 (print), 1650-3740 (online)


This paper presents an integrated method for the simulation of mixed 1D / 3D system models in the domain of building energy supply systems. The feasibility of this approach is demonstrated by the use case of a solar thermal system: the sub-model of a hot water storage is modeled as a detailed threedimensional CFD model; but the rest of the system model (solar collector; hydraulics; heat exchanger; controller etc.) is modeled as a simplified component-based DAE model. For this purpose; the hot water storage model is simulated with ANSYS CFD. This detailed sub-model is embedded in the solar thermal system model; which consists of component models of the Modelica library FluidFlow and is simulated with Dymola. The numerical coupling and integration of both sub-models is realized by the use of the co-simulation environment TISC. With a comparison of a pure Modelica system model and a mixed 1D / 3D system model of the same solar thermal system; advantages and disadvantages of both simulation approaches are worked out.


Co-simulation; Mixed 1D/3D modeling; energy building and plant simulation


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