@inproceedings{HendlerExtraLockanetal., author = {Hendler, Marco and Extra, Simon and Lockan, Michael and Bestle, Dieter and Flassig, Peter Michael}, title = {Compressor Design in the Context of Holistic Aero Engine Design}, series = {2017 AIAA Aviation Forum, Denver, AIAA-2017-3334, 2017}, booktitle = {2017 AIAA Aviation Forum, Denver, AIAA-2017-3334, 2017}, doi = {10.2514/6.2017-3334}, language = {en} } @inproceedings{ExtraLockanBestleetal., author = {Extra, Simon and Lockan, Michael and Bestle, Dieter and Flassig, Peter Michael}, title = {A Comparison of Strategies for Efficient Core Engine Optimization with Coupled Subsystems}, series = {Proceedings of Montreal 2018, Global Power and Propulsion Forum, 7-9.05.2018}, booktitle = {Proceedings of Montreal 2018, Global Power and Propulsion Forum, 7-9.05.2018}, pages = {8}, abstract = {The present paper compares four different optimization strategies for decoupled optimization in the context of preliminary core engine design for aero engines. An optimization with the AAO (All-At-Once) approach is performed as a baseline and compared against the performance and results of three cascaded optimization strategies: CO (Collaborative Optimization), BLISS 2000 (Bi-Level Integrated System Synthesis) and ISOC (Interface Segmentation Optimization Concept). The optimization problem is based on a thermodynamic core engine model representing an industrial application example. The results are assessed with respect to typical requirements for multidisciplinary core engine design. The impact of the used optimization strategy on the performance of the optimization concept is investigated and discussed.}, language = {en} } @inproceedings{ExtraLockanBestleetal., author = {Extra, Simon and Lockan, Michael and Bestle, Dieter and Flassig, Peter Michael}, title = {Coupled Subsystem Optimization for Preliminary Core Engine Design}, series = {Evolutionary and deterministic methods for design optimization and control with applications to industrial and societal problems, Sep. 13-15, 2017 in Madrid, Spain, EUROGEN 2017, Book of abstracts}, booktitle = {Evolutionary and deterministic methods for design optimization and control with applications to industrial and societal problems, Sep. 13-15, 2017 in Madrid, Spain, EUROGEN 2017, Book of abstracts}, publisher = {Technical University}, address = {Madrid}, isbn = {978-84-697-5112-1}, language = {en} } @inproceedings{ExtraLockanBestleetal., author = {Extra, Simon and Lockan, Michael and Bestle, Dieter and Flassig, Peter Michael}, title = {Coupled Subsystem Optimiziation for Preliminary Core Engine Design}, series = {Evolutionary and Deterministic Methods for Design Optimization and Control With Applications to Industrial and Societal Problems}, booktitle = {Evolutionary and Deterministic Methods for Design Optimization and Control With Applications to Industrial and Societal Problems}, editor = {Andr{\`e}s-P{\`e}rez, Esther and Gonz{\´a}lez, Leo M. and Periaux, Jacques and Gauger, Nicolas R. and Quagliarella, Domenico and Giannakoglou, Kyriakos C.}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-319-89889-6}, doi = {10.1007/978-3-319-89890-2_33}, pages = {513 -- 527}, language = {en} } @inproceedings{LockanBestle, author = {Lockan, Michael and Bestle, Dieter}, title = {Robustheitsaspekte in verteilten Entwicklungsumgebungen}, series = {4. Dresdener Probabilistik Workshop, 06.10. - 07.10.2011, Dresden}, booktitle = {4. Dresdener Probabilistik Workshop, 06.10. - 07.10.2011, Dresden}, pages = {16}, language = {de} } @inproceedings{LockanBestle, author = {Lockan, Michael and Bestle, Dieter}, title = {A Concept for Collaborative Design and Distributed Optimisation}, series = {5th IC-SCCE International Conference: From Scientific Computing to Computational Engineering, Athen, 2012}, booktitle = {5th IC-SCCE International Conference: From Scientific Computing to Computational Engineering, Athen, 2012}, isbn = {978-960-98941-9-7}, abstract = {The paper shows a methodology for designing a complex system in a collaborative design environment by sharing information on autonomous subsystems and coupling parameters. Collaborative design is a current issue in aviation industry where intellectual property rights of individual companies prohibit a common evaluation model. State of the art approaches based on nested local optimisation loops are not sufficient if time-consuming component analyses are involved. A new approach for collaborative design is developed where the overall optimisation of a complex system is split into subsystem optimisation problems. Coupling parameters are treated as local design variables and only optimal coupling parameters are exchanged regularly. Application to a test example shows a huge time reduction and improved probability for finding the global optimum. Advantages are also demonstrated for an industrial design task.}, language = {en} } @inproceedings{AmtsfeldLockanBestleetal., author = {Amtsfeld, Philipp and Lockan, Michael and Bestle, Dieter and Meyer, Markus}, title = {Accelerated 3D Aerodynamic Optimization of Gas Turbine Blades}, series = {ASME Turbo Expo 2014, Turbine Technical Conference and Exposition, Volume 2B: Turbomachinery, D{\"u}sseldorf, Germany, June 16-20, 2014}, booktitle = {ASME Turbo Expo 2014, Turbine Technical Conference and Exposition, Volume 2B: Turbomachinery, D{\"u}sseldorf, Germany, June 16-20, 2014}, publisher = {ASME}, address = {New York, NY}, isbn = {978-0-7918-4561-5}, pages = {9}, language = {en} } @inproceedings{LockanAmtsfeldBestleetal., author = {Lockan, Michael and Amtsfeld, Philipp and Bestle, Dieter and Meyer, Marcus}, title = {Non-Linear Sensitivity Analysis Based on Regression Trees with Apllication to 3D Aerodynamic Optimization of Gas Turbine Blades}, series = {International Conference on Engineering and Applied Scieces Optimization (OPT-i), Kos, Griechenland, 2014}, booktitle = {International Conference on Engineering and Applied Scieces Optimization (OPT-i), Kos, Griechenland, 2014}, isbn = {978-960-99994-5-8}, language = {en} } @inproceedings{LockanBestleJankeetal., author = {Lockan, Michael and Bestle, Dieter and Janke, Christian and Meyer, Marcus}, title = {Optimization of Coupled System Components Using Approximations of Interface Quantities}, series = {ASME Turbo Expo 2017, Turbomachinery Conference and Exposition, Volume 2C, Turbomachinery Charlotte, North Carolina, USA, June 26-30, 2017}, booktitle = {ASME Turbo Expo 2017, Turbomachinery Conference and Exposition, Volume 2C, Turbomachinery Charlotte, North Carolina, USA, June 26-30, 2017}, publisher = {ASME}, address = {New York, NY}, isbn = {978-0-7918-5080-0}, doi = {10.1115/GT2017-64135}, pages = {11}, language = {en} } @phdthesis{Lockan, author = {Lockan, Michael}, title = {Kooperative Optimierung komplexer Systeme durch Segmentierung des Interface-Raums}, publisher = {Shaker Verlag GmbH}, address = {Aachen}, isbn = {978-3-8440-5455-2}, pages = {XIV, 181}, abstract = {Die Auslegung von komplexen technischen Systemen ist ein Prozess, bei welchem Experten verschiedener Disziplinen, Abteilungen oder sogar Firmen sehr eng zusammenarbeiten m{\"u}ssen. Aufgrund der Komplexit{\"a}t oder auch aus politischen Gr{\"u}nden existiert im Allgemeinen eine einzelne System-Analyse nicht und unterschiedliche Subsystem-Analysen m{\"u}ssen in geeigneter Weise gekoppelt werden, um das Verhalten des Gesamtsystems zu bestimmen. Dabei stellt besonders in kooperativen Entwicklungsumgebungen, wenn m{\"o}glicherweise konkurrierende Firmen zusammenarbeiten m{\"u}ssen, diese Kopplung eine große Herausforderung dar. Die Optimierung von komplexen Systemen findet heutzutage haupts{\"a}chlich im Rahmen von automatisierten Subsystem-Optimierungen statt. Die Schnittstellen zwischen den einzelnen Subsystemen werden dabei in fr{\"u}hen Entwurfsphasen auf Grundlage von Erfahrungswerten oder einfacher Absch{\"a}tzungen festgelegt und nachfolgend nicht mehr wesentlich ver{\"a}ndert. Diese Schnittstellen bestimmen jedoch maßgeblich die erreichbare Leistungsf{\"a}higkeit des Systems, und sollten daher w{\"a}hrend des gesamten Optimierungsprozesses unter Verwendung detaillierter Subsystem-Analysen hinterfragt und gezielt angepasst werden. Die daf{\"u}r ben{\"o}tigten multidisziplin{\"a}ren Optimierungsverfahren m{\"u}ssen dabei alle beteiligten Analysemodelle in effizienter Weise koordinieren, damit eine Anwendung in praktischen Problemstellungen und hohen Entwurfsraumdimensionen erfolgen kann. Der Fokus dieser Arbeit liegt daher auf der Entwicklung eines effizienten Verfahrens zur Optimierung komplexer Systeme unter besonderer Beachtung eines kooperativen Hintergrundes. Es wird gezeigt, wie Antwortfl{\"a}chen-Verfahren verwendet werden k{\"o}nnen, um die Subsystem-Optimierungen zu beschleunigen und somit auch zeitaufw{\"a}ndige Analysen im Rahmen einer System-Optimierung einzusetzen. Durch die Analyse bestehender Verfahren wird die generelle Struktur kooperativer Optimierungen verdeutlicht und eine Einordnung des entwickelten ISOC-Verfahrens erm{\"o}glicht. Dessen ausf{\"u}hrliche Herleitung und Darstellung zeigt die einfache Anpassung der vorhandenen Subsystem-Prozesse und demonstriert die Einbindung in die System-Optimierung. Die Anwendungen auf repr{\"a}sentative Probleme aus der Triebwerkstechnik zeigen zum Einen die Vorteile paralleler und entkoppelter Optimierungen, und zum Anderen, dass das entwickelte ISOC-Verfahren in der Lage ist, praktische Problemstellungen zu l{\"o}sen.}, language = {de} } @techreport{BestleLockanHartwigetal., author = {Bestle, Dieter and Lockan, Michael and Hartwig, Lennard and Martin, Ivo}, title = {Q3D Optimierung vielstufiger Verdichter in der Vorauslegung und robuste multidisziplin{\"a}re Schaufelauslegung}, publisher = {Brandenburgische Technische Universit{\"a}t Cottbus-Senftenberg, IKMZ-Universit{\"a}tsbibliothek}, address = {Cottbus ; Senftenberg}, isbn = {978-3-940471-30-7}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-42225}, pages = {33}, language = {de} } @misc{KrieseLockanSchaffrathetal., author = {Kriese, Maximilian and Lockan, Michael and Schaffrath, Robert and Stathopoulos, Panagiotis}, title = {Quasi-static simulation of a start-up procedure for a multistage centrifugal compression system}, series = {Proceedings of ASME Turbo Expo 2025 : Turbomachinery Technical Conference and Exposition, June 16-20, 2025, Memphis, Tennessee : Volume 4 : Controls, Diagnostics \& Instrumentation; Cycle Innovations; Education; Electric Power}, journal = {Proceedings of ASME Turbo Expo 2025 : Turbomachinery Technical Conference and Exposition, June 16-20, 2025, Memphis, Tennessee : Volume 4 : Controls, Diagnostics \& Instrumentation; Cycle Innovations; Education; Electric Power}, publisher = {American Society of Mechanical Engineers}, address = {New York, NY}, isbn = {978-0-7918-8880-3}, doi = {10.1115/GT2025-151935}, pages = {12}, abstract = {In order to achieve the European Union's climate protection targets by 2050, energy use in the private and industrial sectors must be switched from using fossil fuels to renewable energy. For industry, this might require that the production processes itself needed to be changed or new technologies to manufacture in a sustainable way needed to be introduced. One example of the latter mentioned are high-temperature heat pumps (HTHP), which will be capable to generate sustainable process heat up to 300°C e.g. for the pulp and paper or food industry. There are currently only a few HTHPs commercially available that can reach temperatures above 150°C. In order to overcome the technological challenges to reach 300°C, two HTHP prototypes are currently developed at the Institute of Low-Carbon Industrial Processes of the German Aerospace Centre (DLR). One of them is the pilot plant ZiRa which is based on the reversed Rankine process and uses steam as its working medium. Herein three centrifugal compressors are applied to achieve a saturated steam temperature of 200°C at the sink. The safe speed-up of these three compressors, titled as the start-up procedure, from the standstill of each compressors up to their respective nominal speed, is modelled in the flow chart software EBSILON Professional. In addition to the compressors, all necessary components, i.e. the intercoolers, the fittings and valves, the pipes, the separators and the bypasses are modelled so that all parameters influencing the thermodynamic inlet state of the respective compressor are considered. The start-up of the multi-stage compression system of the pilot plan ZiRa is shown as a quasi-static time series. As a first step, the speed increments are defined. Afterwards, absolute pressures between 1.25 and 2 bar upstream of the first compressor and their effect on the operation of the subsequent compressor stages, are analyzed. Therefore, the mass flow rates and rotational speeds are specified manually at first so that an executable, editable model is created. Based on these results, the operation of the compressors are optimized in order to ensure a surge margin of 15 \% and to avoid choke in each operating point.}, language = {en} }