@article{EschPischingerHagenetal.1998,
  author    = {Esch, Thomas and Pischinger, M. and Hagen, J. and Salber, W.},
  title     = {M{\"o}glichkeiten der ottomotorischen Prozeßf{\"u}hrung bei Verwendung des elektromechanischen Ventiltriebs},
  pages     = {987 -- 1015},
  year      = {1998},
  language  = {de}
}
@article{EschSalberKemperetal.2001,
  author    = {Esch, Thomas and Salber, W. and Kemper, Hans and Staay, F. van der},
  title     = {Der elektromechanische Ventiltrieb - Systembaustein f{\"u}r zuk{\"u}nftige Antriebskonzepte, Teil 2.},
  series = {Motortechnische Zeitschrift (MTZ).},
  volume    = {62},
  journal   = {Motortechnische Zeitschrift (MTZ).},
  number    = {1},
  publisher = {Springer Nature},
  address   = {Basel},
  issn      = {0024-8525},
  doi       = {10.1007/bf03227081},
  pages     = {44 -- 55},
  year      = {2001},
  language  = {de}
}
@article{EschSalberKemperetal.2000,
  author    = {Esch, Thomas and Salber, W. and Kemper, Hans and Staay, F. van der},
  title     = {Der elektromechanische Ventiltrieb - Systembaustein f{\"u}r zuk{\"u}nftige Antriebskonzepte, Teil 1.},
  series = {Motortechnische Zeitschrift (MTZ).},
  volume    = {61},
  journal   = {Motortechnische Zeitschrift (MTZ).},
  number    = {12},
  publisher = {Springer Nature},
  address   = {Basel},
  issn      = {0024-8525},
  doi       = {10.1007/bf03227081},
  pages     = {826 -- 836},
  year      = {2000},
  language  = {de}
}
@article{EschSalberWoltersetal.2002,
  author    = {Esch, Thomas and Salber, Wolfgang and Wolters, Peter and Geiger, Jos{\´e} and Dilthey, Jochen},
  title     = {Synergies of variable valve actuation and direct injection},
  series = {Direct injection SI engine technology 2002 : [SAE 2002 world congress, Detroit, Michigan, USA, March 4 - 7, 2002].},
  journal   = {Direct injection SI engine technology 2002 : [SAE 2002 world congress, Detroit, Michigan, USA, March 4 - 7, 2002].},
  publisher = {Society of Automotive Engineers},
  address   = {Warrendale, Pa},
  isbn      = {0-7680-0961-8},
  pages     = {45 -- 53},
  year      = {2002},
  language  = {en}
}
@article{EschSaupeFahletal.1994,
  author    = {Esch, Thomas and Saupe, T. and Fahl, E. and Koch, F.},
  title     = {Verbrauchseinsparung durch bedarfsgerechten Antrieb der Nebenaggregate},
  series = {Motortechnische Zeitschrift. 55 (1994), H. 7/8},
  journal   = {Motortechnische Zeitschrift. 55 (1994), H. 7/8},
  isbn      = {0024-8525},
  pages     = {416 -- 431},
  year      = {1994},
  language  = {de}
}
@article{EschWoltersSalberetal.2001,
  author    = {Esch, Thomas and Wolters, P. and Salber, W. and Geiger, J.},
  title     = {Variable Ventilsteuerung und Direkteinspritzung - vom Wettbewerb zur Synergie},
  series = {Motor und Umwelt 2001, Internal Combustion Engine Versus Fuel Cell - Potential and Limitations as Automotive Power Sources, Verbrennungsmotor versus Brennstoffzelle - Potenziale und Grenzen f{\"u}r den Automobilantrieb, Proc., Graz, AT, 6.-7. Sep, 2001},
  journal   = {Motor und Umwelt 2001, Internal Combustion Engine Versus Fuel Cell - Potential and Limitations as Automotive Power Sources, Verbrennungsmotor versus Brennstoffzelle - Potenziale und Grenzen f{\"u}r den Automobilantrieb, Proc., Graz, AT, 6.-7. Sep, 2001},
  pages     = {183 -- 206},
  year      = {2001},
  language  = {de}
}
@article{FayyaziSardarThomasetal.2023,
  author    = {Fayyazi, Mojgan and Sardar, Paramjotsingh and Thomas, Sumit Infent and Daghigh, Roonak and Jamali, Ali and Esch, Thomas and Kemper, Hans and Langari, Reza and Khayyam, Hamid},
  title     = {Artificial intelligence/machine learning in energy management systems, control, and optimization of hydrogen fuel cell vehicles},
  volume    = {15},
  number    = {6},
  publisher = {MDPI},
  address   = {Basel},
  doi       = {10.3390/su15065249},
  pages     = {38},
  year      = {2023},
  abstract  = {Environmental emissions, global warming, and energy-related concerns have accelerated the advancements in conventional vehicles that primarily use internal combustion engines. Among the existing technologies, hydrogen fuel cell electric vehicles and fuel cell hybrid electric vehicles may have minimal contributions to greenhouse gas emissions and thus are the prime choices for environmental concerns. However, energy management in fuel cell electric vehicles and fuel cell hybrid electric vehicles is a major challenge. Appropriate control strategies should be used for effective energy management in these vehicles. On the other hand, there has been significant progress in artificial intelligence, machine learning, and designing data-driven intelligent controllers. These techniques have found much attention within the community, and state-of-the-art energy management technologies have been developed based on them. This manuscript reviews the application of machine learning and intelligent controllers for prediction, control, energy management, and vehicle to everything (V2X) in hydrogen fuel cell vehicles. The effectiveness of data-driven control and optimization systems are investigated to evolve, classify, and compare, and future trends and directions for sustainability are discussed.},
  language  = {en}
}
@misc{FeldmannFranckeEspeetal.2022,
  author    = {Feldmann, Marco and Francke, Gero and Espe, Clemes and Chen, Qian and Baader, Fabian and Boxberg, Marc S. and Sustrate, Anna-Marie and Kowalski, Julia and Dachwald, Bernd},
  title     = {Performance data of an ice-melting probe from field tests in two different ice environments},
  doi       = {10.5281/zenodo.6094866},
  year      = {2022},
  abstract  = {This dataset was acquired at field tests of the steerable ice-melting probe "EnEx-IceMole" (Dachwald et al., 2014). A field test in summer 2014 was used to test the melting probe's system, before the probe was shipped to Antarctica, where, in international cooperation with the MIDGE project, the objective of a sampling mission in the southern hemisphere summer 2014/2015 was to return a clean englacial sample from the subglacial brine reservoir supplying the Blood Falls at Taylor Glacier (Badgeley et al., 2017, German et al., 2021). The standardized log-files generated by the IceMole during melting operation include more than 100 operational parameters, housekeeping information, and error states, which are reported to the base station in intervals of 4 s. Occasional packet loss in data transmission resulted in a sparse number of increased sampling intervals, which where compensated for by linear interpolation during post processing. The presented dataset is based on a subset of this data: The penetration distance is calculated based on the ice screw drive encoder signal, providing the rate of rotation, and the screw's thread pitch. The melting speed is calculated from the same data, assuming the rate of rotation to be constant over one sampling interval. The contact force is calculated from the longitudinal screw force, which es measured by strain gauges. The used heating power is calculated from binary states of all heating elements, which can only be either switched on or off. Temperatures are measured at each heating element and averaged for three zones (melting head, side-wall heaters and back-plate heaters).},
  language  = {en}
}
@article{Finger2016,
  author    = {Finger, Felix},
  title     = {Senkrechtstarter: FH-Absolvent wird f{\"u}r Transportdrohne ausgezeichnet},
  series = {campushunter: das etwas andere Karrieremagazin - Wintersemester 16/17},
  journal   = {campushunter: das etwas andere Karrieremagazin - Wintersemester 16/17},
  number    = {17. Regionalausgabe Aachen},
  publisher = {Campushunter Media},
  address   = {Heidelberg},
  issn      = {2196-9426},
  pages     = {116 -- 117},
  year      = {2016},
  language  = {de}
}
@article{Finger2017,
  author    = {Finger, Felix},
  title     = {Vergleichende Leistungs- und Nutzenbewertung von VTOL- und CTOL-UAVs},
  series = {Luft- und Raumfahrt : informieren, vernetzen, f{\"o}rdern / Hrsg.: Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt},
  volume    = {38},
  journal   = {Luft- und Raumfahrt : informieren, vernetzen, f{\"o}rdern / Hrsg.: Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt},
  number    = {1},
  issn      = {0173-6264},
  pages     = {44 -- 47},
  year      = {2017},
  language  = {de}
}
@inproceedings{Finger2016,
  author    = {Finger, Felix},
  title     = {Comparative Performance and Benefit Assessment of VTOL and CTOL UAVs},
  series = {Deutscher Luft- und Raumfahrtkongress (DLRK) 2016, 13.-15.9.2016},
  booktitle = {Deutscher Luft- und Raumfahrtkongress (DLRK) 2016, 13.-15.9.2016},
  pages     = {10 Seiten},
  year      = {2016},
  language  = {en}
}
@article{FingerBilBraun2019,
  author    = {Finger, Felix and Bil, Cees and Braun, Carsten},
  title     = {Initial Sizing Methodology for Hybrid-Electric General Aviation Aircraft},
  series = {Journal of Aircraft},
  volume    = {57},
  journal   = {Journal of Aircraft},
  number    = {2},
  issn      = {1533-3868},
  doi       = {10.2514/1.C035428},
  pages     = {245 -- 255},
  year      = {2019},
  language  = {en}
}
@inproceedings{FingerBraunBil2018,
  author    = {Finger, Felix and Braun, Carsten and Bil, Cees},
  title     = {Case studies in initial sizing for hybrid-electric general aviation aircraft},
  series = {2018 AIAA/IEEE Electric Aircraft Technologies Symposium, Cincinnati, Ohio},
  booktitle = {2018 AIAA/IEEE Electric Aircraft Technologies Symposium, Cincinnati, Ohio},
  doi       = {10.2514/6.2018-5005},
  year      = {2018},
  language  = {en}
}
@article{FingerBraunBil2018,
  author    = {Finger, Felix and Braun, Carsten and Bil, Cees},
  title     = {Impact of electric propulsion technology and mission requirements on the performance of VTOL UAVs},
  series = {CEAS Aeronautical Journal},
  volume    = {10},
  journal   = {CEAS Aeronautical Journal},
  number    = {3},
  publisher = {Springer},
  issn      = {1869-5582 print},
  doi       = {10.1007/s13272-018-0352-x},
  pages     = {843},
  year      = {2018},
  abstract  = {One of the engineering challenges in aviation is the design of transitioning vertical take-off and landing (VTOL) aircraft. Thrust-borne flight implies a higher mass fraction of the propulsion system, as well as much increased energy consumption in the take-off and landing phases. This mass increase is typically higher for aircraft with a separate lift propulsion system than for aircraft that use the cruise propulsion system to support a dedicated lift system. However, for a cost-benefit trade study, it is necessary to quantify the impact the VTOL requirement and propulsion configuration has on aircraft mass and size. For this reason, sizing studies are conducted. This paper explores the impact of considering a supplemental electric propulsion system for achieving hovering flight. Key variables in this study, apart from the lift system configuration, are the rotor disk loading and hover flight time, as well as the electrical systems technology level for both batteries and motors. Payload and endurance are typically used as the measures of merit for unmanned aircraft that carry electro-optical sensors, and therefore the analysis focuses on these particular parameters.},
  language  = {en}
}
@inproceedings{FingerBraunBil2017,
  author    = {Finger, Felix and Braun, Carsten and Bil, Cees},
  title     = {The Impact of Electric Propulsion on the Performance of VTOL UAVs},
  series = {Deutscher Luft- und Raumfahrtkongress 2017, DLRK , M{\"u}nchen},
  booktitle = {Deutscher Luft- und Raumfahrtkongress 2017, DLRK , M{\"u}nchen},
  year      = {2017},
  language  = {en}
}
@inproceedings{FingerBraunBil2017,
  author    = {Finger, Felix and Braun, Carsten and Bil, Cees},
  title     = {A Review of Configuration Design for Distributed Propulsion Transitioning VTOL Aircraft},
  series = {Asia-Pacific International Symposium on Aerospace Technology 2017, APISAT 2017, Seoul, Korea},
  booktitle = {Asia-Pacific International Symposium on Aerospace Technology 2017, APISAT 2017, Seoul, Korea},
  pages     = {15 Seiten},
  year      = {2017},
  language  = {en}
}
@inproceedings{FingerBraunBil2019,
  author    = {Finger, Felix and Braun, Carsten and Bil, Cees},
  title     = {Impact of Engine Failure Constraints on the Initial Sizing of Hybrid-Electric GA Aircraft},
  series = {AIAA Scitech 2019 Forum},
  booktitle = {AIAA Scitech 2019 Forum},
  doi       = {10.2514/6.2019-1812},
  year      = {2019},
  language  = {en}
}
@article{FingerBraunBil2020,
  author    = {Finger, Felix and Braun, Carsten and Bil, Cees},
  title     = {Comparative assessment of parallel-hybrid-electric propulsion systems for four different aircraft},
  series = {Journal of Aircraft},
  volume    = {57},
  journal   = {Journal of Aircraft},
  number    = {5},
  publisher = {AIAA},
  address   = {Reston, Va.},
  issn      = {1533-3868},
  doi       = {10.2514/1.C035897},
  year      = {2020},
  abstract  = {Until electric energy storage systems are ready to allow fully electric aircraft, the combination of combustion engine and electric motor as a hybrid-electric propulsion system seems to be a promising intermediate solution. Consequently, the design space for future aircraft is expanded considerably, as serial hybrid-electric, parallel hybrid-electric, fully electric, and conventional propulsion systems must all be considered. While the best propulsion system depends on a multitude of requirements and considerations, trends can be observed for certain types of aircraft and certain types of missions. This Paper provides insight into some factors that drive a new design toward either conventional or hybrid propulsion systems. General aviation aircraft, regional transport aircraft vertical takeoff and landing air taxis, and unmanned aerial vehicles are chosen as case studies. Typical missions for each class are considered, and the aircraft are analyzed regarding their takeoff mass and primary energy consumption. For these case studies, a high-level approach is chosen, using an initial sizing methodology. Only parallel-hybrid-electric powertrains are taken into account. Aeropropulsive interaction effects are neglected. Results indicate that hybrid-electric propulsion systems should be considered if the propulsion system is sized by short-duration power constraints. However, if the propulsion system is sized by a continuous power requirement, hybrid-electric systems offer hardly any benefit.},
  language  = {en}
}
@inproceedings{FingerBraunBil2020,
  author    = {Finger, Felix and Braun, Carsten and Bil, Cees},
  title     = {Comparative assessment of parallel-hybrid-electric propulsion systems for four different aircraft},
  series = {AIAA SciTech Forum 2020, 06.01.2020 - 10.01.2020, Orlando},
  booktitle = {AIAA SciTech Forum 2020, 06.01.2020 - 10.01.2020, Orlando},
  doi       = {10.2514/6.2020-1502},
  pages     = {15 Seiten},
  year      = {2020},
  language  = {en}
}
@article{FingerBraunBil2020,
  author    = {Finger, Felix and Braun, Carsten and Bil, Cees},
  title     = {Impact of Battery Performance on the Initial Sizing of Hybrid-Electric General Aviation Aircraft},
  series = {Journal of Aerospace Engineering},
  volume    = {33},
  journal   = {Journal of Aerospace Engineering},
  number    = {3},
  publisher = {ASCE},
  address   = {Reston, Va.},
  issn      = {1943-5525},
  doi       = {10.1061/(ASCE)AS.1943-5525.0001113},
  year      = {2020},
  abstract  = {Studies suggest that hybrid-electric aircraft have the potential to generate fewer emissions and be inherently quieter when compared to conventional aircraft. By operating combustion engines together with an electric propulsion system, synergistic benefits can be obtained. However, the performance of hybrid-electric aircraft is still constrained by a battery's energy density and discharge rate. In this paper, the influence of battery performance on the gross mass for a four-seat general aviation aircraft with a hybrid-electric propulsion system is analyzed. For this design study, a high-level approach is chosen, using an innovative initial sizing methodology to determine the minimum required aircraft mass for a specific set of requirements and constraints. Only the peak-load shaving operational strategy is analyzed. Both parallel- and serial-hybrid propulsion configurations are considered for two different missions. The specific energy of the battery pack is varied from 200 to 1,000 W⋅h/kg, while the discharge time, and thus the normalized discharge rating (C-rating), is varied between 30 min (2C discharge rate) and 2 min (30C discharge rate). With the peak-load shaving operating strategy, it is desirable for hybrid-electric aircraft to use a light, low capacity battery system to boost performance. For this case, the battery's specific power rating proved to be of much higher importance than for full electric designs, which have high capacity batteries. Discharge ratings of 20C allow a significant take-off mass reduction aircraft. The design point moves to higher wing loadings and higher levels of hybridization if batteries with advanced technology are used.},
  language  = {en}
}
@inproceedings{FingerdeVriesVosetal.2020,
  author    = {Finger, Felix and de Vries, Reynard and Vos, Roelof and Braun, Carsten and Bil, Cees},
  title     = {A comparison of hybrid-electric aircraft sizing methods},
  series = {AIAA Scitech 2020 Forum},
  booktitle = {AIAA Scitech 2020 Forum},
  doi       = {10.2514/6.2020-1006},
  pages     = {31 Seiten},
  year      = {2020},
  language  = {en}
}
@article{FingerGoetten2019,
  author    = {Finger, Felix and G{\"o}tten, Falk},
  title     = {Neue Ans{\"a}tze f{\"u}r die Entwicklung von unbemannten Flugger{\"a}ten},
  series = {Ingenieurspiegel},
  volume    = {2019},
  journal   = {Ingenieurspiegel},
  number    = {1},
  isbn      = {1868-5919},
  pages     = {67 -- 68},
  year      = {2019},
  abstract  = {Wie sieht das unbemannte Flugzeug von {\"U}bermorgen aus? Dieser Frage stellen sich Forscher an der Fachhochschule Aachen. Die weltweit rasant fortschreitende Entwicklung des Marktes f{\"u}r unbemannte Flugger{\"a}te (UAVs - „Unmanned Aerial Vehicles") bietet großes Potenzial f{\"u}r Wachstum und Wertsch{\"o}pfung. Unbemannte fliegende Systeme k{\"o}nnen - f{\"u}r bestimmte Anwendungsgebiete - wesentlich g{\"u}nstiger, kleiner und effizienter ausgelegt werden als bemannte L{\"o}sungen. Dabei sind sich viele Unternehmen {\"u}ber das m{\"o}gliche Potential dieser Technologie noch gar nicht bewusst.},
  language  = {de}
}
@inproceedings{FingerGoettenBraun2018,
  author    = {Finger, Felix and G{\"o}tten, Falk and Braun, Carsten},
  title     = {Initial Sizing for a Family of Hybrid-Electric VTOL General Aviation Aircraft},
  series = {67. Deutscher Luft- und Raumfahrtkongress 2018},
  booktitle = {67. Deutscher Luft- und Raumfahrtkongress 2018},
  pages     = {14 S.},
  year      = {2018},
  language  = {en}
}
@inproceedings{FingerGoettenBraunetal.2019,
  author    = {Finger, Felix and G{\"o}tten, Falk and Braun, Carsten and Bil, C.},
  title     = {On Aircraft Design Under the Consideration of Hybrid-Electric Propulsion Systems},
  series = {APISAT 2018: The Proceedings of the 2018 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2018)},
  booktitle = {APISAT 2018: The Proceedings of the 2018 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2018)},
  publisher = {Springer},
  address   = {Singapore},
  isbn      = {978-981-13-3305-7},
  doi       = {10.1007/978-981-13-3305-7_99},
  pages     = {1261 -- 1272},
  year      = {2019},
  abstract  = {A hybrid-electric propulsion system combines the advantages of fuel-based systems and battery powered systems and offers new design freedom. To take full advantage of this technology, aircraft designers must be aware of its key differences, compared to conventional, carbon-fuel based, propulsion systems. This paper gives an overview of the challenges and potential benefits associated with the design of aircraft that use hybrid-electric propulsion systems. It offers an introduction of the most popular hybrid-electric propulsion architectures and critically assess them against the conventional and fully electric propulsion configurations. The effects on operational aspects and design aspects are covered. Special consideration is given to the application of hybrid-electric propulsion technology to both unmanned and vertical take-off and landing aircraft. The authors conclude that electric propulsion technology has the potential to revolutionize aircraft design. However, new and innovative methods must be researched, to realize the full benefit of the technology.},
  language  = {en}
}
@inproceedings{FingerGoettenBraunetal.2019,
  author    = {Finger, Felix and G{\"o}tten, Falk and Braun, Carsten and Bil, Cees},
  title     = {Mass, Primary Energy, and Cost - The Impact of Optimization Objectives on the Initial Sizing of Hybrid-Electric General Aviation Aircraft},
  series = {Deutscher Luft- und Raumfahrtkongress 2019, DLRK 2019. Darmstadt, Germany},
  booktitle = {Deutscher Luft- und Raumfahrtkongress 2019, DLRK 2019. Darmstadt, Germany},
  doi       = {10.25967/490012},
  pages     = {1 -- 17},
  year      = {2019},
  language  = {en}
}
@article{FingerGoettenBraunetal.2020,
  author    = {Finger, Felix and G{\"o}tten, Falk and Braun, Carsten and Bil, Cees},
  title     = {Mass, primary energy, and cost: the impact of optimization objectives on the initial sizing of hybrid-electric general aviation aircraft},
  series = {CEAS Aeronautical Journal},
  volume    = {2020},
  journal   = {CEAS Aeronautical Journal},
  number    = {11},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1869-5590},
  doi       = {10.1007/s13272-020-00449-8},
  pages     = {713 -- 730},
  year      = {2020},
  abstract  = {For short take-off and landing (STOL) aircraft, a parallel hybrid-electric propulsion system potentially offers superior performance compared to a conventional propulsion system, because the short-take-off power requirement is much higher than the cruise power requirement. This power-matching problem can be solved with a balanced hybrid propulsion system. However, there is a trade-off between wing loading, power loading, the level of hybridization, as well as range and take-off distance. An optimization method can vary design variables in such a way that a minimum of a particular objective is attained. In this paper, a comparison between the optimization results for minimum mass, minimum consumed primary energy, and minimum cost is conducted. A new initial sizing algorithm for general aviation aircraft with hybrid-electric propulsion systems is applied. This initial sizing methodology covers point performance, mission performance analysis, the weight estimation process, and cost estimation. The methodology is applied to the design of a STOL general aviation aircraft, intended for on-demand air mobility operations. The aircraft is sized to carry eight passengers over a distance of 500 km, while able to take off and land from short airstrips. Results indicate that parallel hybrid-electric propulsion systems must be considered for future STOL aircraft.},
  language  = {en}
}
@inproceedings{FingerGoettenBraunetal.2019,
  author    = {Finger, Felix and G{\"o}tten, Falk and Braun, Carsten and Bil, Cees},
  title     = {Cost Estimation Methods for Hybrid-Electric General Aviation Aircraft},
  series = {Asia Pacific International Symposium on Aerospace Technology. APISAT 2019},
  booktitle = {Asia Pacific International Symposium on Aerospace Technology. APISAT 2019},
  pages     = {1 -- 13},
  year      = {2019},
  language  = {en}
}
@inproceedings{FingerKhalsaKreyeretal.2019,
  author    = {Finger, Felix and Khalsa, R. and Kreyer, J{\"o}rg and Mayntz, Joscha and Braun, Carsten and Dahmann, Peter and Esch, Thomas and Kemper, Hans and Schmitz, O. and Bragard, Michael},
  title     = {An approach to propulsion system modelling for the conceptual design of hybrid-electric general aviation aircraft},
  series = {Deutscher Luft- und Raumfahrtkongress 2019, 30.9.-2.10.2019, Darmstadt},
  booktitle = {Deutscher Luft- und Raumfahrtkongress 2019, 30.9.-2.10.2019, Darmstadt},
  pages     = {15 Seiten},
  year      = {2019},
  abstract  = {In this paper, an approach to propulsion system modelling for hybrid-electric general aviation aircraft is presented. Because the focus is on general aviation aircraft, only combinations of electric motors and reciprocating combustion engines are explored. Gas turbine hybrids will not be considered. The level of the component's models is appropriate for the conceptual design stage. They are simple and adaptable, so that a wide range of designs with morphologically different propulsive system architectures can be quickly compared. Modelling strategies for both mass and efficiency of each part of the propulsion system (engine, motor, battery and propeller) will be presented.},
  language  = {en}
}
@article{FischerKowalskiPudasaini2012,
  author    = {Fischer, Jan-Thomas and Kowalski, Julia and Pudasaini, Shiva P.},
  title     = {Topographic curvature effects in applied avalanche modelling},
  series = {Cold Regions Science and Technology},
  volume    = {74-75},
  journal   = {Cold Regions Science and Technology},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1872-7441},
  doi       = {10.1016/j.coldregions.2012.01.005},
  pages     = {21 -- 30},
  year      = {2012},
  abstract  = {This paper describes the implementation of topographic curvature effects within the RApid Mass MovementS (RAMMS) snow avalanche simulation toolbox. RAMMS is based on a model similar to shallow water equations with a Coulomb friction relation and the velocity dependent Voellmy drag. It is used for snow avalanche risk assessment in Switzerland. The snow avalanche simulation relies on back calculation of observed avalanches. The calibration of the friction parameters depends on characteristics of the avalanche track. The topographic curvature terms are not yet included in the above mentioned classical model. Here, we fundamentally improve this model by mathematically and physically including the topographic curvature effects. By decomposing the velocity dependent friction into a topography dependent term that accounts for a curvature enhancement in the Coulomb friction, and a topography independent contribution similar to the classical Voellmy drag, we construct a general curvature dependent frictional resistance, and thus propose new extended model equations. With three site-specific examples, we compare the apparent frictional resistance of the new approach, which includes topographic curvature effects, to the classical one. Our simulation results demonstrate substantial effects of the curvature on the flow dynamics e.g., the dynamic pressure distribution along the slope. The comparison of resistance coefficients between the two models demonstrates that the physically based extension presents an improvement to the classical approach. Furthermore a practical example highlights its influence on the pressure outline in the run out zone of the avalanche. Snow avalanche dynamics modeling natural terrain curvature centrifugal force friction coefficients.},
  language  = {en}
}
@article{FischerKowalskiPudasainietal.2009,
  author    = {Fischer, Jan-Thomas and Kowalski, Julia and Pudasaini, Shiva P. and Miller, S. A.},
  title     = {Dynamic Avalanche Modeling in Natural Terrain},
  series = {International Snow Science Workshop, Davos 2009, Proceedings ; Proc. ISSW 2009},
  journal   = {International Snow Science Workshop, Davos 2009, Proceedings ; Proc. ISSW 2009},
  pages     = {448 -- 452},
  year      = {2009},
  abstract  = {The powerful avalanche simulation toolbox RAMMS (Rapid Mass Movements) is based on a depth-averaged hydrodynamic system of equations with a Voellmy-Salm friction relation. The two empirical friction parameters μ and � correspond to a dry Coulomb friction and a viscous resistance, respectively. Although μ and � lack a proper physical explanation, 60 years of acquired avalanche data in the Swiss Alps made a systematic calibration possible. RAMMS can therefore successfully model avalanche flow depth, velocities, impact pressure and run out distances. Pudasaini and Hutter (2003) have proposed extended, rigorously derived model equations that account for local curvature and twist. A coordinate transformation into a reference system, applied to the actual mountain topography of the natural avalanche path, is performed. The local curvature and the twist of the avalanche path induce an additional term in the overburden pressure. This leads to a modification of the Coulomb friction, the free-surface pressure gradient, the pressure induced by the channel, and the gravity components along and normal to the curved and twisted reference surface. This eventually guides the flow dynamics and deposits of avalanches. In the present study, we investigate the influence of curvature on avalanche flow in real mountain terrain. Simulations of real avalanche paths are performed and compared for the different models approaches. An algorithm to calculate curvature in real terrain is introduced in RAMMS. This leads to a curvature dependent friction relation in an extended version of the Voellmy-Salm model equations. Our analysis provides yet another step in interpreting the physical meaning and significance of the friction parameters used in the RAMMS computational environment.},
  language  = {en}
}
@article{FornaciariGuidettiHavermannetal.2010,
  author    = {Fornaciari, Andrea and Guidetti, Marco and Havermann, Marc and Lettini, Antonio},
  title     = {Maccine mobili pi{\`u} efficienti},
  series = {Fluidotecnica},
  journal   = {Fluidotecnica},
  number    = {345},
  publisher = {Quine Business Publisher},
  address   = {Milano},
  pages     = {11 -- 14},
  year      = {2010},
  abstract  = {Secondo le attuali normative tutte le macchine mobili, entro il 2012, dovranno essere soggette a un incremento di efficienza energetica. Un'evoluzione del sistema idraulico potr{\`a} contribuire in maniera significativa al miglioramento richiesto. Elettronica e idraulica sempre pi{\`u} protagoniste.},
  language  = {it}
}
@article{FrankeBosisNapoli2001,
  author    = {Franke, Thomas and Bosis, R. and Napoli, M.-D.},
  title     = {{\"U}ber das Internet steuerbarer Gebl{\"a}sepr{\"u}fstand mit einstellbaren Eintrittsleitschaufeln},
  series = {Virtuelle Instrumente in der Praxis : Begleitband zum Kongreß VIP 2001 / Rahman Jamal ; Hans Jaschinski},
  journal   = {Virtuelle Instrumente in der Praxis : Begleitband zum Kongreß VIP 2001 / Rahman Jamal ; Hans Jaschinski},
  publisher = {H{\"u}thig Verlag},
  address   = {Heidelberg [u.a.]},
  isbn      = {3-7785-2829-7},
  pages     = {219 -- 225},
  year      = {2001},
  language  = {de}
}
@phdthesis{Frotscher2016,
  author    = {Frotscher, Ralf},
  title     = {Electromechanical modeling and simulation of thin cardiac tissue constructs - smoothed FEM applied to a biomechanical plate problem},
  year      = {2016},
  language  = {en}
}
@book{Funke2001,
  author    = {Funke, Harald},
  title     = {Analyse der Temperatur- und Str{\"o}mungsungleichf{\"o}rmigkeiten in mehrstufigen Turbinen / Harald Funke},
  publisher = {Mainz},
  address   = {Aachen},
  isbn      = {3-89653-400-9},
  pages     = {VI, 135 S. : Ill., graph. Darst.},
  year      = {2001},
  language  = {de}
}
@book{Funke2008,
  author    = {Funke, Harald},
  title     = {Optimierung und Miniaturisierung der Mikro-Misch-Diffusionsverbrennung von Wasserstoff zur potentiellen Anwendung in einer Ultra-Gasturbine. Schlussbericht.},
  publisher = {Fachhochschule Aachen},
  address   = {Aachen},
  pages     = {85 S.},
  year      = {2008},
  language  = {de}
}
@article{FunkeBeckmann2022,
  author    = {Funke, Harald and Beckmann, Nils},
  title     = {Flexible fuel operation of a Dry-Low-NOx Micromix Combustor with Variable Hydrogen Methane Mixture},
  series = {International Journal of Gas Turbine, Propulsion and Power Systems},
  volume    = {13},
  journal   = {International Journal of Gas Turbine, Propulsion and Power Systems},
  number    = {2},
  issn      = {1882-5079},
  pages     = {1 -- 7},
  year      = {2022},
  abstract  = {The role of hydrogen (H2) as a carbon-free energy carrier is discussed since decades for reducing greenhouse gas emissions. As bridge technology towards a hydrogen-based energy supply, fuel mixtures of natural gas or methane (CH4) and hydrogen are possible. The paper presents the first test results of a low-emission Micromix combustor designed for flexible-fuel operation with variable H2/CH4 mixtures. The numerical and experimental approach for considering variable fuel mixtures instead of recently investigated pure hydrogen is described. In the experimental studies, a first generation FuelFlex Micromix combustor geometry is tested at atmospheric pressure at gas turbine operating conditions corresponding to part- and full-load. The H2/CH4 fuel mixture composition is varied between 57 and 100 vol.\% hydrogen content. Despite the challenges flexible-fuel operation poses onto the design of a combustion system, the evaluated FuelFlex Micromix prototype shows a significant low NOx performance},
  language  = {en}
}
@inproceedings{FunkeBeckmann2019,
  author    = {Funke, Harald and Beckmann, Nils},
  title     = {Flexible Fuel Operation of a Dry-Low-Nox Micromix Combustor with Variable Hydrogen Methane Mixtures},
  series = {Proceedings of International Gas Turbine Congress 2019 Tokyo, November 17-22, 2019, Tokyo, Japan},
  booktitle = {Proceedings of International Gas Turbine Congress 2019 Tokyo, November 17-22, 2019, Tokyo, Japan},
  isbn      = {978-4-89111-010-9},
  year      = {2019},
  language  = {en}
}
@article{FunkeBeckmannAbanteriba2019,
  author    = {Funke, Harald and Beckmann, Nils and Abanteriba, Sylvester},
  title     = {An overview on dry low NOx micromix combustor development for hydrogen-rich gas turbine applications},
  series = {International Journal of Hydrogen Energy},
  volume    = {44},
  journal   = {International Journal of Hydrogen Energy},
  number    = {13},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0360-3199},
  doi       = {10.1016/j.ijhydene.2019.01.161},
  pages     = {6978 -- 6990},
  year      = {2019},
  language  = {en}
}
@inproceedings{FunkeBeckmannAbanteriba2017,
  author    = {Funke, Harald and Beckmann, Nils and Abanteriba, Sylvester},
  title     = {A comparison of complex chemistry mechanisms for hydrogen methane blends based on the Sandia / Sydney Bluff-Body Flame HM1},
  series = {Proceedings of the Eleventh Asia-Pacific Conference on Combustion (ASPACC 2017), New South Wales, Australia, 10-14 December 2017},
  booktitle = {Proceedings of the Eleventh Asia-Pacific Conference on Combustion (ASPACC 2017), New South Wales, Australia, 10-14 December 2017},
  isbn      = {978-1-5108-5646-2},
  pages     = {262 -- 265},
  year      = {2017},
  language  = {en}
}
@inproceedings{FunkeBeckmannAbanteriba2019,
  author    = {Funke, Harald and Beckmann, Nils and Abanteriba, Sylvester},
  title     = {Development and Testing of a FuelFlex Dry-Low-NOx Micromix Combustor for Industrial Gas Turbine Applications With Variable Hydrogen Methane Mixtures},
  series = {ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. June 17-21, 2019 Phoenix, Arizona, USA. Volume 4A: Combustion, Fuels, and Emissions},
  booktitle = {ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. June 17-21, 2019 Phoenix, Arizona, USA. Volume 4A: Combustion, Fuels, and Emissions},
  isbn      = {978-0-7918-5861-5},
  doi       = {10.1115/GT2019-90095},
  pages     = {11 Seiten},
  year      = {2019},
  language  = {en}
}
@article{FunkeBeckmannKeinzetal.2016,
  author    = {Funke, Harald and Beckmann, Nils and Keinz, Jan and Abanteriba, Sylvester},
  title     = {Comparison of Numerical Combustion Models for Hydrogen and Hydrogen-Rich Syngas Applied for Dry-Low-NOx-Micromix-Combustion},
  series = {ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition Volume 4A: Combustion, Fuels and Emissions Seoul, South Korea, June 13-17, 2016},
  journal   = {ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition Volume 4A: Combustion, Fuels and Emissions Seoul, South Korea, June 13-17, 2016},
  publisher = {ASME},
  address   = {New York, NY},
  isbn      = {978-0-7918-4975-0},
  doi       = {10.1115/GT2016-56430},
  pages     = {12},
  year      = {2016},
  abstract  = {The Dry-Low-NOₓ (DLN) Micromix combustion technology has been developed as low emission combustion principle for industrial gas turbines fueled with hydrogen or syngas. The combustion process is based on the phenomenon of jet-in-crossflow-mixing. Fuel is injected perpendicular into the air-cross-flow and burned in a multitude of miniaturized, diffusion-like flames. The miniaturization of the flames leads to a significant reduction of NOₓ emissions due to the very short residence time of reactants in the flame. In the Micromix research approach, CFD analyses are validated towards experimental results. The combination of numerical and experimental methods allows an efficient design and optimization of DLN Micromix combustors concerning combustion stability and low NOₓ emissions. The paper presents a comparison of several numerical combustion models for hydrogen and hydrogen-rich syngas. They differ in the complexity of the underlying reaction mechanism and the associated computational effort. For pure hydrogen combustion a one-step global reaction is applied using a hybrid Eddy-Break-up model that incorporates finite rate kinetics. The model is evaluated and compared to a detailed hydrogen combustion mechanism derived by Li et al. including 9 species and 19 reversible elementary reactions. Based on this mechanism, reduction of the computational effort is achieved by applying the Flamelet Generated Manifolds (FGM) method while the accuracy of the detailed reaction scheme is maintained. For hydrogen-rich syngas combustion (H₂-CO) numerical analyses based on a skeletal H₂/CO reaction mechanism derived by Hawkes et al. and a detailed reaction mechanism provided by Ranzi et al. are performed. The comparison between combustion models and the validation of numerical results is based on exhaust gas compositions available from experimental investigation on DLN Micromix combustors. The conducted evaluation confirms that the applied detailed combustion mechanisms are able to predict the general physics of the DLN-Micromix combustion process accurately. The Flamelet Generated Manifolds method proved to be generally suitable to reduce the computational effort while maintaining the accuracy of detailed chemistry. Especially for reaction mechanisms with a high number of species accuracy and computational effort can be balanced using the FGM model.},
  language  = {en}
}
@inproceedings{FunkeBeckmannKeinzetal.2017,
  author    = {Funke, Harald and Beckmann, Nils and Keinz, Jan and Abanteriba, Sylvester},
  title     = {Numerical and Experimental Evaluation of a Dual-Fuel Dry-Low-NOx Micromix Combustor for Industrial Gas Turbine Applications},
  series = {Proceedings of the ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. Volume 4B: Combustion, Fuels and Emissions. Charlotte, North Carolina, USA. June 26-30, 2017},
  booktitle = {Proceedings of the ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. Volume 4B: Combustion, Fuels and Emissions. Charlotte, North Carolina, USA. June 26-30, 2017},
  publisher = {ASME},
  address   = {New York},
  isbn      = {978-0-7918-5085-5},
  doi       = {10.1115/GT2017-64795},
  year      = {2017},
  abstract  = {The Dry-Low-NOx (DLN) Micromix combustion technology has been developed originally as a low emission alternative for industrial gas turbine combustors fueled with hydrogen. Currently the ongoing research process targets flexible fuel operation with hydrogen and syngas fuel. The non-premixed combustion process features jet-in-crossflow-mixing of fuel and oxidizer and combustion through multiple miniaturized flames. The miniaturization of the flames leads to a significant reduction of NOx emissions due to the very short residence time of reactants in the flame. The paper presents the results of a numerical and experimental combustor test campaign. It is conducted as part of an integration study for a dual-fuel (H2 and H2/CO 90/10 Vol.\%) Micromix combustion chamber prototype for application under full scale, pressurized gas turbine conditions in the auxiliary power unit Honeywell Garrett GTCP 36-300. In the presented experimental studies, the integration-optimized dual-fuel Micromix combustor geometry is tested at atmospheric pressure over a range of gas turbine operating conditions with hydrogen and syngas fuel. The experimental investigations are supported by numerical combustion and flow simulations. For validation, the results of experimental exhaust gas analyses are applied. Despite the significantly differing fuel characteristics between pure hydrogen and hydrogen-rich syngas the evaluated dual-fuel Micromix prototype shows a significant low NOx performance and high combustion efficiency. The combustor features an increased energy density that benefits manufacturing complexity and costs.},
  language  = {en}
}
@article{FunkeBeckmannKeinzetal.2018,
  author    = {Funke, Harald and Beckmann, Nils and Keinz, Jan and Abanteriba, Sylvester},
  title     = {Comparison of Numerical Combustion Models for Hydrogen and Hydrogen-Rich Syngas Applied for Dry-Low-Nox-Micromix-Combustion},
  series = {Journal of Engineering for Gas Turbines and Power},
  volume    = {140},
  journal   = {Journal of Engineering for Gas Turbines and Power},
  number    = {8},
  publisher = {ASME},
  address   = {New York, NY},
  issn      = {0742-4795},
  doi       = {10.1115/1.4038882},
  pages     = {9 Seiten},
  year      = {2018},
  abstract  = {The Dry-Low-NOx (DLN) Micromix combustion technology has been developed as low emission combustion principle for industrial gas turbines fueled with hydrogen or syngas. The combustion process is based on the phenomenon of jet-in-crossflow-mixing (JICF). Fuel is injected perpendicular into the air-cross-flow and burned in a multitude of miniaturized, diffusion-like flames. The miniaturization of the flames leads to a significant reduction of NOx emissions due to the very short residence time of reactants in the flame. In the Micromix research approach, computational fluid dynamics (CFD) analyses are validated toward experimental results. The combination of numerical and experimental methods allows an efficient design and optimization of DLN Micromix combustors concerning combustion stability and low NOx emissions. The paper presents a comparison of several numerical combustion models for hydrogen and hydrogen-rich syngas. They differ in the complexity of the underlying reaction mechanism and the associated computational effort. The performance of a hybrid eddy-break-up (EBU) model with a one-step global reaction is compared to a complex chemistry model and a flamelet generated manifolds (FGM) model, both using detailed reaction schemes for hydrogen or syngas combustion. Validation of numerical results is based on exhaust gas compositions available from experimental investigation on DLN Micromix combustors. The conducted evaluation confirms that the applied detailed combustion mechanisms are able to predict the general physics of the DLN-Micromix combustion process accurately. The FGM method proved to be generally suitable to reduce the computational effort while maintaining the accuracy of detailed chemistry.},
  language  = {en}
}
@article{FunkeBeckmannKeinzetal.2019,
  author    = {Funke, Harald and Beckmann, Nils and Keinz, Jan and Abanteriba, Sylvester},
  title     = {Numerical and Experimental Evaluation of a Dual-Fuel Dry-Low-NOx Micromix Combustor for Industrial Gas Turbine Applications},
  series = {Journal of Thermal Science and Engineering Applications},
  volume    = {11},
  journal   = {Journal of Thermal Science and Engineering Applications},
  number    = {1},
  publisher = {ASME},
  address   = {New York},
  issn      = {19485085},
  doi       = {10.1115/1.4041495},
  pages     = {011015},
  year      = {2019},
  language  = {en}
}
@inproceedings{FunkeBeckmannKeinzetal.2021,
  author    = {Funke, Harald and Beckmann, Nils and Keinz, Jan and Horikawa, Atsushi},
  title     = {30 years of dry low NOx micromix combustor research for hydrogen-rich fuels: an overview of past and present activities},
  series = {Proceedings of the ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition, September 21-25, 2020, Virtual, Online. Vol.: 4B: Combustion, Fuels, and Emissions},
  booktitle = {Proceedings of the ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition, September 21-25, 2020, Virtual, Online. Vol.: 4B: Combustion, Fuels, and Emissions},
  publisher = {American Society of Mechanical Engineers (ASME)},
  isbn      = {978-0-7918-8413-3},
  doi       = {10.1115/GT2020-16328},
  pages     = {14 Seiten},
  year      = {2021},
  language  = {en}
}
@inproceedings{FunkeBeckmannStefanetal.2023,
  author    = {Funke, Harald and Beckmann, Nils and Stefan, Lukas and Keinz, Jan},
  title     = {Hydrogen combustor integration study for a medium range aircraft engine using the dry-low NOx "Micromix" combustion principle},
  series = {Proceedings of the ASME Turbo Expo 2023: Turbomachinery Technical Conference and Exposition. Volume 1: Aircraft Engine. Boston, Massachusetts, USA. June 26-30, 2023},
  booktitle = {Proceedings of the ASME Turbo Expo 2023: Turbomachinery Technical Conference and Exposition. Volume 1: Aircraft Engine. Boston, Massachusetts, USA. June 26-30, 2023},
  publisher = {ASME},
  address   = {New York},
  isbn      = {978-0-7918-8693-9},
  doi       = {10.1115/GT2023-102370},
  pages     = {12 Seiten},
  year      = {2023},
  abstract  = {The feasibility study presents results of a hydrogen combustor integration for a Medium-Range aircraft engine using the Dry-Low-NOₓ Micromix combustion principle. Based on a simplified Airbus A320-type flight mission, a thermodynamic performance model of a kerosene and a hydrogen-powered V2530-A5 engine is used to derive the thermodynamic combustor boundary conditions. A new combustor design using the Dry-Low NOx Micromix principle is investigated by slice model CFD simulations of a single Micromix injector for design and off-design operation of the engine. Combustion characteristics show typical Micromix flame shapes and good combustion efficiencies for all flight mission operating points. Nitric oxide emissions are significant below ICAO CAEP/8 limits. For comparison of the Emission Index (EI) for NOₓ emissions between kerosene and hydrogen operation, an energy (kerosene) equivalent Emission Index is used. A full 15° sector model CFD simulation of the combustion chamber with multiple Micromix injectors including inflow homogenization and dilution and cooling air flows investigates the combustor integration effects, resulting NOₓ emission and radial temperature distributions at the combustor outlet. The results show that the integration of a Micromix hydrogen combustor in actual aircraft engines is feasible and offers, besides CO₂ free combustion, a significant reduction of NOₓ emissions compared to kerosene operation.},
  language  = {en}
}
@article{FunkeBoernerFalketal.2011,
  author    = {Funke, Harald and B{\"o}rner, Sebastian and Falk, F. and Hendrick, P.},
  title     = {Control system modifications and their effects on the operation of a hydrogen-fueled Auxiliary Power Unit},
  series = {XX international symposium on air breathing engines 2011 : ISABE 2011, Gothenburg, Sweden, 12-16 September, 2011. Vol. 2.},
  journal   = {XX international symposium on air breathing engines 2011 : ISABE 2011, Gothenburg, Sweden, 12-16 September, 2011. Vol. 2.},
  publisher = {American Institute of Aeronautics and Astronautics},
  address   = {Reston, VA},
  isbn      = {9781618391803},
  pages     = {929 -- 938},
  year      = {2011},
  language  = {en}
}
@incollection{FunkeBoernerHendricketal.2011,
  author    = {Funke, Harald and B{\"o}rner, Sebastian and Hendrick, P. and Recker, E.},
  title     = {Modification and testing of an engine and fuel control system for a hydrogen fuelled gas turbine},
  series = {Progress in Propulsion Physics. Vol. 2},
  booktitle = {Progress in Propulsion Physics. Vol. 2},
  publisher = {EDP Sciences},
  address   = {Les Ulis},
  isbn      = {978-2-7598-0673-7},
  pages     = {475 -- 486},
  year      = {2011},
  language  = {en}
}
@inproceedings{FunkeBoernerHendricketal.2013,
  author    = {Funke, Harald and B{\"o}rner, Sebastian and Hendrick, P. and Recker, E. and Elsing, R.},
  title     = {Development and integration of a scalable low NOx combustion chamber for a hydrogen fuelled aero gas turbine},
  series = {Progress in Propulsion Physics. - Vol. 4},
  booktitle = {Progress in Propulsion Physics. - Vol. 4},
  editor    = {DeLuca, Luigi T.},
  publisher = {EDP Sciences},
  address   = {[Les Ulis]},
  isbn      = {978-2-7598-0876-2},
  doi       = {10.1051/eucass/201304357},
  pages     = {357 -- 372},
  year      = {2013},
  language  = {en}
}
@inproceedings{FunkeBoernerKeinzetal.2012,
  author    = {Funke, Harald and B{\"o}rner, Sebastian and Keinz, Jan and Hendrick, P. and Recker, E.},
  title     = {Low NOx Hydrogen combustion chamber for industrial gas turbine applications", 14th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery},
  series = {ISROMAC-14 : the Forteenth International Symposium on Transport Phenomena and Dynamics of Rotating Machinery ; Honolulu, Hawaii, February 27 - March 02nd, 2012},
  booktitle = {ISROMAC-14 : the Forteenth International Symposium on Transport Phenomena and Dynamics of Rotating Machinery ; Honolulu, Hawaii, February 27 - March 02nd, 2012},
  year      = {2012},
  language  = {en}
}