@inproceedings{FunkeEschRoosen2009,
  author    = {Funke, Harald and Esch, Thomas and Roosen, Peter},
  title     = {Using motor gasoline for aircrafts - coping with growing bio-fuel-caused risks by understanding cause-effect relationship},
  series = {Fuels 2009 : mineral oil based and alternative fuels ; 7th international colloquium ; January 14 - 15, 2009},
  booktitle = {Fuels 2009 : mineral oil based and alternative fuels ; 7th international colloquium ; January 14 - 15, 2009},
  editor    = {Bartz, Wilfried J.},
  publisher = {Technische Akademie Esslingen (TAE)},
  address   = {Ostfildern},
  isbn      = {978-3-924813-75-8},
  pages     = {237 -- 244},
  year      = {2009},
  abstract  = {The utilisation of vehicle-oriented gasoline in general aviation is very desirable for both ecological and economical reasons, as well as for general considerations of availability. As of today vehicle fuels may be used if the respective engine and cell are certified for such an operation. For older planes a supplementary technical certificate is provided for gasoline mixtures with less than 1 \% v/v ethanol only, though. Larger admixtures of ethanol may lead to sudden engine malfunction and should be considered as considerable security risks. Major problems are caused by the partially ethanol non-withstanding materials, a necessarily changed stochiometric adjustment of the engine for varying ethanol shares and the tendency for phase separation in the presence of absorbed water. The concepts of the flexible fuel vehicles are only partially applicable in the view of air security.},
  language  = {en}
}
@article{RobinsonRoennaFunke2007,
  author    = {Robinson, A. E. and R{\"o}nna, Uwe and Funke, Harald},
  title     = {Testing of a 10 kW diffusive micro-mix combustor for hydrogen-fuelled micro-scale gas turbines},
  series = {International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau> ; PowerMEMS ; 7},
  journal   = {International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau> ; PowerMEMS ; 7},
  pages     = {225 -- 228},
  year      = {2007},
  language  = {en}
}
@article{BecretGrossenTrillaetal.2007,
  author    = {B{\´e}cret, P. and Grossen, J. and Trilla, J. and Robinson, A. and Bosschaerts, W. and Funke, Harald and Hendrick, P.},
  title     = {Testing and numerical study of a 10 kW hydrogen micro combustor},
  series = {International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau> ; PowerMEMS ; 7},
  journal   = {International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau> ; PowerMEMS ; 7},
  pages     = {367 -- 370},
  year      = {2007},
  language  = {en}
}
@inproceedings{FunkeKeinzBoerneretal.2016,
  author    = {Funke, Harald and Keinz, Jan and B{\"o}rner, S. and Hendrick, P. and Elsing, R.},
  title     = {Testing and analysis of the impact on engine cycle parameters and control system modifications using hydrogen or methane as fuel in an industrial gas turbine},
  series = {Progress in propulsion physics ; Volume 8},
  booktitle = {Progress in propulsion physics ; Volume 8},
  publisher = {EDP Sciences},
  address   = {o.O.},
  organization    = {European Conference for Aerospace Sciences <2013, M{\"u}nchen>},
  isbn      = {978-5-94588-191-4},
  doi       = {10.1051/eucass/201608409},
  pages     = {409 -- 426},
  year      = {2016},
  language  = {en}
}
@article{BohnFunkeGier1999,
  author    = {Bohn, D. and Funke, Harald and Gier, J.},
  title     = {Temperature jet development in a cross-over channel},
  series = {Third European Conference on Turbomachinery - fluid dynamics and thermodynamics : : 2 - 5 March 1999, Royal National Hotel, London, UK / organized by the Energy Transfer and Thermofluid Mechanics Group of the Institution of Mechanical Engineers (IMechE); with support and sponsorship from European Commission / Vol. B.},
  journal   = {Third European Conference on Turbomachinery - fluid dynamics and thermodynamics : : 2 - 5 March 1999, Royal National Hotel, London, UK / organized by the Energy Transfer and Thermofluid Mechanics Group of the Institution of Mechanical Engineers (IMechE); with support and sponsorship from European Commission / Vol. B.},
  publisher = {Professional Engineering Publ.},
  address   = {Bury St. Edmunds},
  pages     = {671 -- 680},
  year      = {1999},
  language  = {en}
}
@techreport{EschFunkeRoosen2010,
  author    = {Esch, Thomas and Funke, Harald and Roosen, Petra},
  title     = {SIoBiA - Safety Implications of Biofuels in Aviation},
  publisher = {EASA},
  address   = {K{\"o}ln},
  pages     = {279 Seiten},
  year      = {2010},
  abstract  = {Biofuels potentially interesting also for aviation purposes are predominantly liquid fuels produced from biomass. The most common biofuels today are biodiesel and bioethanol. Since diesel engines are rather rare in aviation this survey is focusing on ethanol admixed to gasoline products. The Directive 2003/30/EC of the European Parliament and the Council of May 8th 2003 on the promotion of the use of biofuels or other renewable fuels for transport encourage a growing admixture of biogenic fuel components to fossil automotive gasoline. Some aircraft models equipped with spark ignited piston engines are approved for operation with automotive gasoline, frequently called "MOGAS" (motor gasoline). The majority of those approvals is limited to MOGAS compositions that do not contain methanol or ethanol beyond negligible amounts. In the past years (bio-)MTBE or (bio-)ETBE have been widely used as blending component of automotive gasoline whilst the usage of low-molecular alcohols like methanol or ethanol has been avoided due to the handling problems especially with regard to the strong affinity for water. With rising mandatory bio-admixtures the conversion of the basic biogenic ethanol to ETBE, causing a reduction of energetic payoff, becomes more and more unattractive. Therefore the direct ethanol admixture is accordingly favoured. Due to the national enforcements of the directive 2003/30/EC more oxygenates produced from organic materials like bioethanol have started to appear in automotive gasolines already. The current fuel specification EN 228 already allows up to 3 \% volume per volume (v/v) (bio-)methanol or up to 5 \% v/v (bio-)ethanol as fuel components. This is also roughly the amount of biogenic components to comply with the legal requirements to avoid monetary penalties for producers and distributors of fuels. Since automotive fuel is cheaper than the common aviation gasoline (AVGAS), creates less problems with lead deposits in the engine, and in general produces less pollutants it is strongly favoured by pilots. But being designed for a different set of usage scenarios the use of automotive fuel with low molecular alcohols for aircraft operation may have adverse effects in aviation operation. Increasing amounts of ethanol admixtures impose various changes in the gasoline's chemical and physical properties, some of them rather unexpected and not within the range of flight experiences even of long-term pilots.},
  language  = {en}
}
@article{FunkeEschRoosen2022,
  author    = {Funke, Harald and Esch, Thomas and Roosen, Petra},
  title     = {Powertrain Adaptions for LPG Usage in General Aviation},
  series = {MTZ worldwide},
  volume    = {2022},
  journal   = {MTZ worldwide},
  number    = {83},
  publisher = {Springer Nature},
  address   = {Basel},
  doi       = {10.1007/s38313-021-0756-6},
  pages     = {58 -- 62},
  year      = {2022},
  abstract  = {In general aviation, too, it is desirable to be able to operate existing internal combustion engines with fuels that produce less CO₂ than Avgas 100LL being widely used today It can be assumed that, in comparison, the fuels CNG, LPG or LNG, which are gaseous under normal conditions, produce significantly lower emissions. Necessary propulsion system adaptations were investigated as part of a research project at Aachen University of Applied Sciences.},
  language  = {en}
}
@article{FunkeReckerBosschaertsetal.2011,
  author    = {Funke, Harald and Recker, E. and Bosschaerts, W. and Boonen, Q. and B{\"o}rner, Sebastian},
  title     = {Parametrical study of the „Micromix" hydrogen combustion principle},
  series = {10th International Symposium on Experimental and Computational Aerothermodynamics of Internal Flows, ISAIF10-049, Brussels, Belgium, 4-7 July 2011},
  journal   = {10th International Symposium on Experimental and Computational Aerothermodynamics of Internal Flows, ISAIF10-049, Brussels, Belgium, 4-7 July 2011},
  year      = {2011},
  language  = {en}
}
@inproceedings{FunkeHajAyedKustereretal.2014,
  author    = {Funke, Harald and Haj Ayed, A. and Kusterer, K. and Keinz, Jan and Kazari, M. and Kitajima, J. and Horikawa, A. and Okada, K.},
  title     = {Numerical Study on Increased Energy Density for the DLN Micromix Hydrogen Combustion Principle},
  series = {Combustion, Fuels and Emissions (ASME Turbo Expo 2014: Turbine Technical Conference and Exposition : D{\"u}sseldorf, Germany, June 16-20, 2014 ; Vol. 4A)},
  booktitle = {Combustion, Fuels and Emissions (ASME Turbo Expo 2014: Turbine Technical Conference and Exposition : D{\"u}sseldorf, Germany, June 16-20, 2014 ; Vol. 4A)},
  publisher = {ASME},
  address   = {New York, N.Y.},
  isbn      = {978-0-7918-4568-4},
  pages     = {V04AT04A057},
  year      = {2014},
  language  = {en}
}
@inproceedings{StrieganStruthDickhoffetal.2019,
  author    = {Striegan, Constantin J. D. and Struth, Benjamin and Dickhoff, Jens and Kusterer, Karsten and Funke, Harald and Bohn, Dieter},
  title     = {Numerical Simulations of the Micromix DLN Hydrogen Combustion Technology with LES and Comparison to Results of RANS and Experimental Data},
  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},
  pages     = {1 -- 9},
  year      = {2019},
  language  = {en}
}
@inproceedings{KronigerHorikawaFunkeetal.2021,
  author    = {Kroniger, Daniel and Horikawa, Atsushi and Funke, Harald and Pf{\"a}ffle, Franziska},
  title     = {Numerical investigation of micromix hydrogen flames at different combustor pressure levels},
  series = {Proceedings of the International Conference on Power Engineering 2021},
  booktitle = {Proceedings of the International Conference on Power Engineering 2021},
  pages     = {4 Seiten},
  year      = {2021},
  abstract  = {This study investigates the influence of pressure on the temperature distribution of the micromix (MMX) hydrogen flame and the NOx emissions. A steady computational fluid dynamic (CFD) analysis is performed by simulating a reactive flow with a detailed chemical reaction model. The numerical analysis is validated based on experimental investigations. A quantitative correlation is parametrized based on the numerical results. We find, that the flame initiation point shifts with increasing pressure from anchoring behind a downstream located bluff body towards anchoring upstream at the hydrogen jet. The numerical NOx emissions trend regarding to a variation of pressure is in good agreement with the experimental results. The pressure has an impact on both, the residence time within the maximum temperature region and on the peak temperature itself. In conclusion, the numerical model proved to be adequate for future prototype design exploration studies targeting on improving the operating range.},
  language  = {en}
}
@inproceedings{StrieganHajAyedFunkeetal.2017,
  author    = {Striegan, C. and Haj Ayed, A. and Funke, Harald and Loechle, S. and Kazari, M. and Horikawa, A. and Okada, K. and Koga, K.},
  title     = {Numerical combustion and heat transfer simulations and validation for a hydrogen fueled "micromix" test combustor in industrial gas turbine applications},
  series = {Proceedings of the ASME Turbo Expo},
  booktitle = {Proceedings of the ASME Turbo Expo},
  number    = {Volume Part F130041-4B, 2017},
  isbn      = {978-079185085-5},
  doi       = {10.1115/GT2017-64719},
  year      = {2017},
  language  = {en}
}
@article{BohnFunkeGier1999,
  author    = {Bohn, D. and Funke, Harald and Gier, J.},
  title     = {Numerical and Experimental Investigations on the Flow in a 4-Stage Turbine with Special Focus on the Development of a Radial Temperature Streak},
  series = {ASME Turbo Expo 1999, Indianapolis, USA, 1999},
  journal   = {ASME Turbo Expo 1999, Indianapolis, USA, 1999},
  year      = {1999},
  language  = {en}
}
@article{BohnFunkeSuerkenetal.2001,
  author    = {Bohn, Dieter and Funke, Harald and S{\"u}rken, Norbert and Kreitmeier, F.},
  title     = {Numerical and experimental investigations on endwall contouring in a four-stage turbine},
  series = {ASME Turbo Expo Land Sea \& Air 2001 : June 4 - 8, 2001, New Orleans, Louisiana / IGTI, International Gas Turbine Institute. American Society of Mechanical Engineers. International Gas Turbine Institute ..},
  journal   = {ASME Turbo Expo Land Sea \& Air 2001 : June 4 - 8, 2001, New Orleans, Louisiana / IGTI, International Gas Turbine Institute. American Society of Mechanical Engineers. International Gas Turbine Institute ..},
  publisher = {ASME},
  address   = {New York, NY},
  isbn      = {0-7918-3528-6},
  pages     = {CD-Rom},
  year      = {2001},
  language  = {en}
}
@article{BohnFunkeHeueretal.2000,
  author    = {Bohn, Dieter and Funke, Harald and Heuer, Tom and B{\"u}tikofer, J.},
  title     = {Numerical and experimental investigations of the influence of different swirl-ratios on the temperature streak equalization in a 4-stage turbine},
  series = {ASME Turbo Expo 2000 ; Munich, May 8-11 2000},
  journal   = {ASME Turbo Expo 2000 ; Munich, May 8-11 2000},
  address   = {Munich},
  year      = {2000},
  language  = {en}
}
@article{RobinsonFunkeWagemakersetal.2009,
  author    = {Robinson, A. E. and Funke, Harald and Wagemakers, R. and Grossen, J. and Bosschaerts, W. and Hendrick, P.},
  title     = {Numerical and Experimental Investigation of a Micromix Combustor for a Hydrogen Fuelled μ-Scale Gas Turbine},
  series = {Proceedings of the ASME Turbo Expo 2009 : : presented at the 2009 ASME Turbo Expo, June 8 - 12, 2009, Orlando, Florida, USA / sponsored by the International Gas Turbine Institute},
  journal   = {Proceedings of the ASME Turbo Expo 2009 : : presented at the 2009 ASME Turbo Expo, June 8 - 12, 2009, Orlando, Florida, USA / sponsored by the International Gas Turbine Institute},
  publisher = {ASME},
  address   = {New York, NY},
  isbn      = {9780791848869},
  pages     = {253 -- 262},
  year      = {2009},
  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.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{FunkeBoernerKeinzetal.2012,
  author    = {Funke, Harald and B{\"o}rner, Sebastian and Keinz, Jan and Kusterer, K. and Kroninger, D. and Kitajima, J. and Kazari, M. and Horikama, A.},
  title     = {Numerical and experimental characterization of low NOx Micromix combustion principle for industrial hydrogen gas turbine applications},
  series = {Proceedings of ASME Turbo Expo 2012},
  booktitle = {Proceedings of ASME Turbo Expo 2012},
  pages     = {11},
  year      = {2012},
  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}
}