TY - GEN A1 - Mischke, Marcel A1 - Pohl, Michael A1 - Höschler, Klaus A1 - Huppertz, André T1 - GAS PATH DESIGNER – zeiteffiziente Vorauslegung von Triebwerks-Ringräumen und zusätzlichen Strukturen T1 - GAS PATH DESIGNER – Time Efficient Pre-Design of Aero Engine Annulus Contours and Additional Structures T2 - Conference Paper des Deutscher Luft- und Raumfahrtkongress 2020 N2 - Der Beginn einer jeden Triebwerksentwicklung startet mit der Auslegung des Ringraumes des Primärgasstromes. Hier müssen einige vorläufige aber auch grundlegende Entscheidungen zu Entwurfsparametern wie Eintrittsquerschnitte, Subsystemlängen, axiale Stufenanzahl in Verdichter und Turbine, usw. definiert werden. Für die Vorauslegung sollte die Palette an anfänglichen Entwurfsparametern so gering wie möglich gehalten werden, um die Menge an möglichen Ringraumentwürfen nicht frühzeitig einzuschränken. Dieses Paper präsentiert das Vorauslegungswerkzeug „Gas Path Designer“ (GPD), welches in der Lage ist Ringraumentwürfe für Turbotriebwerke über zeiteffiziente Berechnungsmethoden in kürzester Zeit bereitzustellen. Das Interface bietet eine Auswahl an Einstellungen, um die genannten Variationsmöglichkeiten zu unterstützen. Der Aufbau ist übersichtlich, um im Rahmen grundlegender konzeptorientierter Gespräche mit dem Kunden eine schnelle und beidseitig nachvollziehbare Variation und Visualisierung des Konzeptentwurfes zu ermöglichen. Des Weiteren können die erhaltenen Ringraumstrukturen der Triebwerksentwürfe als Leitstruktur für CAD-Programme sowie weiterführende Optimierungsstrategien genutzt werden. N2 - The beginning of each aircraft engine development starts with the design of the annulus contour of the primary gas path. In this case, preliminary but also fundamental decisions on design parameters such as inlet cross sections, subsystem lengths, number of stages in compressor and turbine and many more details have to be defined. For the preliminary design, the amount of initial design parameters should be kept as small as possible. Hence, the amount of possible annulus contours and future aero engine designs will not be limited at an early design stage. This paper presents the design tool "Gas Path Designer" (GPD) which is able to provide annulus designs for aero engines via time efficient calculation methods. The user interface offers a suitable range of settings to support the afore mentioned design variation possibilities. Hence, in the context of basic concept-oriented discussions with customers, the GPD allows a quick and mutually comprehensible variation and visualisation of conceptual designs. Furthermore, the resulting annulus contour of the aircraft engine designs can be used as a reference curves for CAD programs and advanced optimization strategies. KW - Gas Path Designer; Annulus Contour; Generic Preliminary Design; Aircraft Engine Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:101:1-2020121112494640076557 UR - https://publikationen.dglr.de/?tx_dglrpublications_pi1%5bdocument_id%5d=530098 VL - Deutscher Luft- und Raumfahrtkongress 2020 PB - Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V. CY - Bonn ER - TY - GEN A1 - Xie, Tianxiao A1 - Starick, Tommy A1 - Mosgow, Anatol A1 - Berg, Heinz Peter A1 - Höschler, Klaus A1 - Schmidt, Heiko T1 - Thermofluiddynamic pre-design of a primary surface heat exchanger under the influence of heat radiation using 1D/3D coupled simulation method T2 - NAFEMS World Congress 2021, online, 25-29. Oktober 2021 N2 - Within the Framework of the "TurboFuelCell (TFC)" a highly integrated and compact energy conversion system based on Micro Gas Turbine Solid Oxide Fuel Cell (MGT-SOFC) hybrid process is being developed by the team at BTU-Cottbus Senftenberg. This work focuses on the extension of the pre-design process of a primary surface heat exchanger (PSHX), which is a key component for the coupling between MGT and SOFC, using an 1D/3D hybrid simulation method for the understanding of its behaviour under the influence of heat radiation. In a MGT-SOFC hybrid process the high temperature heat exchanger plays an important role in preheating the fresh air to a minimum operation temperature necessary for SOFC. Due to the special location of this PSHX in the TFC, it is constantly exposed to heat radiation from the SOFC module, which requires additional consideration of its influence for better model accuracy. A first design, which is later extended through an 1D Flow network model, based on 𝜖 − 𝑁𝑇𝑈 method is presented. A complete 3D-CFD simulation with consideration of heat radiation is initially employed for the whole flow process to examine the first design. However, this approach proves to be highly computationally expensive due to the large dimensional difference between the plenum for cathode exhaust air and the fine channels in the PSHX. To reduce the computational effort, the flow and heat transfer in the PSHX is modelled by 1D elements. The flow in the plenum is simulated by 3D-CFD, which better accounts for convection and thermal radiation. A comparison between 3D-CFD and 1D/3D hybrid model is performed. A significant reduction of simulation time and computing resources can be achieved for well calibrated hybrid model without compromising on accuracy. In the talk, the effect of insulation layer thickness variations on the heat transfer on the plenum side due to heat radiation and their influence on the heat exchanger efficiency are discussed. Consequently, design improvements are realized based on the previous findings. Finally, the 1D/3D hybrid simulation method is evaluated and prepared for the general applications in thermal management of machines based on coupled MGT-SOFC process. Y1 - 2021 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Starick_2021_NAFEMS_World_Congress_Manuscript.pdf UR - https://agenda.nwc21.org/session.php?s=B5 ER - TY - GEN A1 - Neubauer, Moritz A1 - Genßler, Julia A1 - Radmann, Vincent A1 - Kohlenberg, Fleming A1 - Pohl, Michael A1 - Böhme, Kurt A1 - Knobloch, Karsten A1 - Sarradj, Ennes A1 - Höschler, Klaus A1 - Modler, Niels A1 - Enghardt, Lars T1 - Experimental and Numerical Investigation of Novel Acoustic Liners and Their Design for Aero-Engine Applications T2 - Aerospace N2 - This paper presents a combined experimental and numerical investigation on a novel liner concept for enhanced low-frequency and broadband acoustic attenuation. In particular, two different realizations, derived from conventional Helmholtz resonators (HR) and plate resonators (PR) are investigated, which both deploy flexible materials with material inherent damping. In this context, a comprehensive experimental investigation was carried out focusing the identification and evaluation of various geometric parameters and material properties on the acoustics dissipation and related properties of various materials in a simplified setup of a single Helmholtz resonator with flexible walls (FHR concept). Furthermore, a parameter study based on analytical models was performed for both liner concepts, taking into account material as well as geometric parameters and their effects on transmission loss. In addition, design concepts that enable cylindrical or otherwise curved liner structures and the corresponding manufacturing technologies are presented, while considering essential structural features such as drainage. With respect to the potential application in jet engines, a structural–mechanical analysis considering the relevant load cases to compare and discuss the mechanical performance of a classical HR and the FHR concept liner is presented. Finally, both concepts are evaluated and possible challenges and potentials for further implementation are described. Y1 - 2023 U6 - https://doi.org/10.3390/aerospace10010005 SN - 2226-4310 VL - 10 IS - 1 ER - TY - GEN A1 - Neubauer, Moritz A1 - Pohl, Michael A1 - Kucher, Michael A1 - Böhm, Robert A1 - Höschler, Klaus A1 - Modler, Niels T1 - DMA of TPU Films and the Modelling of Their Viscoelastic Properties for Noise Reduction in Jet Engines T2 - Polymers N2 - Due to current developments in jet engine design, the acoustic performance of conventional acoustic liners needs to be improved with respect to lower frequency spectrums and broadband absorption. In this context, the present study aimed to determine the viscoelastic material properties of a thermoplastic polyurethane (TPU) film for targeted application in novel acoustic liners with integrated film material for enhanced noise reduction. Therefore, a dynamic mechanical analysis (DMA) was performed to determine these viscoelastic material properties. Based on the acquired data, the time-temperature shift (TTS) was applied to obtain the material’s temperature- and frequency-dependent mechanical properties. In this regard, the William-Landel-Ferry (WLF) method and an alternative polynomial approach determining the shift factors were investigated and compared. Furthermore, a generalized Maxwell model—so-called Prony-series—with and without pre-smoothing utilizing of a fractional rheological model was applied to approximate the measured storage and loss modulus and to provide a material model that can be used in finite element analyses. Finally, the results were discussed concerning the application of the films in acoustic liners under the conditions of a standard flight cycle and the applied loads. The present investigations thus provide a method for characterizing polymer materials, approximating their mechanical behavior for vibration applications at different ambient temperatures and enabling the identification of their operational limits during the application in acoustic liners. Y1 - 2022 U6 - https://doi.org/10.3390/polym14235285 SN - 2073-4360 VL - 14 IS - 23 ER - TY - GEN A1 - Kazula, Stefan A1 - Rich, Beatrice Monique A1 - Höschler, Klaus A1 - Woll, Ralf T1 - Interest High School Students in STEM Studies, while Preparing STEM Students for Leading Positions T2 - 2021 IEEE Global Engineering Education Conference Y1 - 2021 SN - 978-1-7281-8478-4 SN - 978-1-7281-8479-1 U6 - https://doi.org/10.1109/EDUCON46332.2021.9454011 VL - 2021 SP - 910 EP - 914 ER - TY - GEN A1 - Kazula, Stefan A1 - Höschler, Klaus T1 - Sustainable Supersonic Transport: a Case Study on Variable Pitot Inlets T2 - 9th European Conference for Aeronautics and Space Sciences (Eucass) Y1 - 2022 UR - https://www.eucass.eu/conferences-and-publications/search-on-this-website?searchword=Sustainable%20Supersonic%20Transport:%20a%20Case%20Study&searchphrase=all&limit=20 U6 - https://doi.org/10.13009/EUCASS2022-4600 ER - TY - GEN A1 - König, Paul A1 - Müller, Phillip A1 - Höschler, Klaus T1 - Assessment of (hybrid)-electric drive-train architectures for future aircraft applications T2 - Journal of Physics: Conference Series N2 - Future regional aircraft and propulsion systems will have to address both a growing market and stricter environmental constraints. Besides the increase of component efficiencies, the technological transformation from conventional to (hybrid)-electric propulsion systems represents a paradigm shift with great potential for the aviation industry. In this context, economic, market-relevant as well as technological boundary conditions for the electrical and mechanical components are developed in this paper for a reference regional aircraft and are based on current research results from different institutions. The propulsion performance analysis of a conventional turboprop is compared and evaluated with a serial-hybrid and a fully-electric configuration (both battery-electric), status today as well as status ~2035, as an example, whereby the presented process can also be applied to other hybrid configurations too. An energy-optimised propulsion and operating concept is derived with regard to minimum resulting system weight. The results of this analysis help to define necessary boundary conditions for future subsystem investigations and identify key research items, especially in the field of the battery. Y1 - 2023 UR - https://iopscience.iop.org/article/10.1088/1742-6596/2526/1/012023 U6 - https://doi.org/10.1088/1742-6596/2526/1/012023 SN - 1742-6596 VL - 2526 ER - TY - GEN A1 - Kazula, Stefan A1 - Höschler, Klaus T1 - Review of variable leading-edge patents for aircraft wings and engine inlets and their relevance for variable pitot inlets in future supersonic transport T2 - CEAS Aeronautical Journal N2 - The motivation for designing variable pitot inlets for future supersonic transport (SST) is explained. A comprehensive overview of existing technological solutions for variable leading edges of aircraft wings and engine inlets is given. The advantages and limitations of over 80 solutions, as well as their relevance for application on variable pitot inlets for SST are described. The challenges of existing solution options concerning design methodologies, level of detail, and experience with a technology are identified. KW - Overview of variable inlet lips KW - Variable aero engine inlet KW - Morphing nacelle intake KW - SST Y1 - 2021 U6 - https://doi.org/10.1007/s13272-021-00520-y SN - 1869-5582 SN - 1869-5590 VL - 12 IS - 3 SP - 685 EP - 700 ER - TY - GEN A1 - König, Paul A1 - Höschler, Klaus A1 - Haridasu, Venkata Brahma Teja T1 - Surface Heat Exchanger Assessment for Battery Powered Aircrafts T2 - AIAA AVIATION Forum, San Diego, 2023 N2 - The thermal management system represents a major challenge for a sustainable transformation of aviation industry from conventional to (hybrid)-electric propulsion. Although component efficiencies of motors, generators, power electronics and batteries are much higher compared to conventional gas turbines, heat dissipation is a challenge if flight characteristics are not to be compromised by massive drag growth. One solution is provided by structural surface heat exchangers, which use the aircraft's wetted surface to reject heat to the environment. Using the temperature-sensitive battery, the potential for fuselage-integrated surface heat exchangers will be evaluated. For this purpose, different flight conditions: take-off, climb, cruise and descent; operational concepts: battery-assisted take-off, battery-assisted climb and recuperative descent, and normal and hot day flight cycles will be investigated using a battery-hybridized reference flight of a Saab 340. A method for calculating reversible and irreversible heat fluxes in the battery is presented and used as a quantitative measure. The theoretical suitability of surface heat exchangers for battery heat rejection can be demonstrated for various flight conditions. Critical design points are not only the take-off but also the battery-assisted climb as well as a too power demanding recuperation during descent. The findings obtained are suitable for use in optimizing operating concepts, identifying suitable charging currents, and for transferability to different aircraft sizes as a function of their take-off weight. KW - Electrical Energy Generation KW - Electrical Storage KW - Electrical Management Y1 - 2023 UR - https://arc.aiaa.org/doi/10.2514/6.2023-4534 U6 - https://doi.org/10.2514/6.2023-4534 SP - 1 EP - 13 PB - American Institute of Aeronautics and Astronautics ER - TY - GEN A1 - Kim, Dogsuk A1 - Asli, Majid A1 - Höschler, Klaus T1 - On the Potentials of the Integration of Pressure Gain Combustion with a Hybrid Electric Propulsion System T2 - Aerospace N2 - As the issue of pollutant emissions from aviation propulsion escalates, research into alternative powertrains is gaining momentum. Two promising technologies are the Hybrid Electric Propulsion System (HEPS) and Pressure Gain Combustion (PGC). HEPS is expected to reduce pollutant emissions by decreasing fuel consumption, whereas PGC uses detonation in the combustor to increase the thermal efficiency of engines by elevating the total pressure during combustion. This study extensively explores the integration of these two emerging technologies, thoroughly assessing the advantages that arise from their combination. First, the renowned turboprop engine PW127 is benchmarked and modeled using Gasturb software. The model is integrated into Simulink using the T-MATS tool, with HEPS and pressure gain components added to analyze the thermodynamics of various configurations under different pressure gain values and HEPS parameters. The analysis, conducted up to the cruise phase of the baseline aircraft, reveals that applying pressure gain combustion through Rotating Detonation Combustion (RDC) results in a more significant increase in efficiency and decrease in fuel consumption compared to HEPS with conventional gas turbines. However, HEPS helps maintain a more uniform combustor inlet condition and reduces the Turbine Inlet Temperature (TIT) at the takeoff phase, where the highest TIT otherwise occurs. The results suggest that integrating HEPS with PGC can be beneficial in maintaining optimal combustor conditions and mitigating turbine efficiency degradation. KW - Pressure gain combustion KW - Hybrid Electric Propulsion KW - Rotating detonation combustion Y1 - 2023 UR - https://www.mdpi.com/2226-4310/10/8/710 U6 - https://doi.org/10.3390/aerospace10080710 SN - 2226-4310 VL - 10 IS - 8 SP - 1 EP - 17 ER -