@article{GermanMikuckiWelchetal.2021,
  author    = {German, Laura and Mikucki, Jill A. and Welch, Susan A. and Welch, Kathleen A. and Lutton, Anthony and Dachwald, Bernd and Kowalski, Julia and Heinen, Dirk and Feldmann, Marco and Francke, Gero and Espe, Clemens and Lyons, W. Berry},
  title     = {Validation of sampling antarctic subglacial hypersaline waters with an electrothermal ice melting probe (IceMole) for environmental analytical geochemistry},
  series = {International Journal of Environmental Analytical Chemistry},
  volume    = {101},
  journal   = {International Journal of Environmental Analytical Chemistry},
  number    = {15},
  publisher = {Taylor \& Francis},
  address   = {London},
  issn      = {0306-7319},
  doi       = {10.1080/03067319.2019.1704750},
  pages     = {2654 -- 2667},
  year      = {2021},
  abstract  = {Geochemical characterisation of hypersaline waters is difficult as high concentrations of salts hinder the analysis of constituents at low concentrations, such as trace metals, and the collection of samples for trace metal analysis in natural waters can be easily contaminated. This is particularly the case if samples are collected by non-conventional techniques such as those required for aquatic subglacial environments. In this paper we present the first analysis of a subglacial brine from Taylor Valley, (~ 78°S), Antarctica for the trace metals: Ba, Co, Mo, Rb, Sr, V, and U. Samples were collected englacially using an electrothermal melting probe called the IceMole. This probe uses differential heating of a copper head as well as the probe's sidewalls and an ice screw at the melting head to move through glacier ice. Detailed blanks, meltwater, and subglacial brine samples were collected to evaluate the impact of the IceMole and the borehole pump, the melting and collection process, filtration, and storage on the geochemistry of the samples collected by this device. Comparisons between melt water profiles through the glacier ice and blank analysis, with published studies on ice geochemistry, suggest the potential for minor contributions of some species Rb, As, Co, Mn, Ni, NH4+, and NO2-+NO3- from the IceMole. The ability to conduct detailed chemical analyses of subglacial fluids collected with melting probes is critical for the future exploration of the hundreds of deep subglacial lakes in Antarctica.},
  language  = {en}
}
@article{SaretzkiBergmannDahmannetal.2021,
  author    = {Saretzki, Charlotte and Bergmann, Ole and Dahmann, Peter and Janser, Frank and Keimer, Jona and Machado, Patricia and Morrison, Audry and Page, Henry and Pluta, Emil and St{\"u}bing, Felix and K{\"u}pper, Thomas},
  title     = {Are small airplanes safe with regards to COVID-19 transmission?},
  series = {Journal of Travel Medicine},
  volume    = {28},
  journal   = {Journal of Travel Medicine},
  number    = {7},
  publisher = {Oxford University Press},
  address   = {Oxford},
  issn      = {1708-8305},
  doi       = {10.1093/jtm/taab105},
  year      = {2021},
  language  = {en}
}
@inproceedings{SchopenKemperEsch2021,
  author    = {Schopen, Oliver and Kemper, Hans and Esch, Thomas},
  title     = {Development of a comparison methodology and evaluation matrix for electrically driven compressors in ICE and FC},
  series = {Proceedings of the 1st UNITED - Southeast Asia Automotive Interest Group (SAIG) International Conference},
  booktitle = {Proceedings of the 1st UNITED - Southeast Asia Automotive Interest Group (SAIG) International Conference},
  publisher = {FH Joanneum},
  address   = {Graz},
  isbn      = {978-3-902103-94-9},
  pages     = {45 -- 46},
  year      = {2021},
  abstract  = {In addition to electromobility and alternative drive systems, a focus is set on electrically driven compressors (EDC), with a high potential for increasing the efficiency of internal combustion engines (ICE) and fuel cells [01]. The primary objective is to increase the ICE torque, provided independently of the ICE speed by compressing the intake air and consequently the ICE filling level supported by the compressor. For operation independent from the ICE speed, the EDC compressor is decoupled from the turbine by using an electric compressor motor (CM) instead of the turbine. ICE performances can be increased by the use of EDC where individual compressor parameters are adapted to the respective application area [02] [03]. This task contains great challenges, increased by demands with regard to pollutant reduction while maintaining constant performance and reduced fuel consumption. The FH-Aachen is equipped with an EDC test bench which enables EDC-investigations in various configurations and operating modes. Characteristic properties of different compressors can be determined, which build the basis for a comparison methodology. Subject of this project is the development of a comparison methodology for EDC with an associated evaluation method and a defined overall evaluation method. For the application of this comparison methodology, corresponding series of measurements are carried out on the EDC test bench using an appropriate test device.},
  language  = {en}
}
@inproceedings{KohlbergerWildKasperetal.2021,
  author    = {Kohlberger, David-Sharif and Wild, Dominik and Kasper, Stefan and Czupalla, Markus},
  title     = {Modeling and analyses of a thermal passively stabilized LEO/GEO star tracker with embedded phase change material applying the Infused Thermal Solutions (ITS) method},
  series = {ICES202: Satellite, Payload, and Instrument Thermal Control},
  booktitle = {ICES202: Satellite, Payload, and Instrument Thermal Control},
  publisher = {Texas Tech University},
  address   = {Lubbock, Tex.},
  pages     = {12 Seiten},
  year      = {2021},
  abstract  = {Phase change materials offer a way of storing excess heat and releasing it when it is needed. They can be utilized as a method to control thermal behavior without the need for additional energy. This work focuses on exploring the potential of using phase change materials to passively control the thermal behavior of a star tracker by infusing it with a fitting phase change material. Based on the numerical model of the star trackers thermal behavior using ESATAN-TMS without implemented phase change material, a fitting phase change material for selected orbits is chosen and implemented in the thermal model. The altered thermal behavior of the numerical model after the implementation is analyzed for different amounts of the chosen phase change materials using an ESATAN-based subroutine developed by the FH Aachen. The PCM-modelling-subroutine is explained in the paper ICES-2021-110. The results show that an increasing amount of phase change material increasingly damps temperature oscillations. Using an integral part structure some of the mass increase can be compensated.},
  language  = {en}
}
@inproceedings{WildCzupallaFoerstner2021,
  author    = {Wild, Dominik and Czupalla, Markus and F{\"o}rstner, Roger},
  title     = {Modeling, prediction and test of additive manufactured integral structures with embedded lattice and phase change material applying Infused Thermal Solutions (ITS)},
  series = {ICES104: Advances in Thermal Control Technology},
  booktitle = {ICES104: Advances in Thermal Control Technology},
  publisher = {Texas Tech University},
  address   = {Lubbock, Tex.},
  pages     = {12 Seiten},
  year      = {2021},
  abstract  = {Infused Thermal Solutions (ITS) introduces a method for passive thermal control to stabilize structural components thermally without active heating and cooling systems, but with phase change material (PCM) for thermal energy storage (TES), in combination with lattice - both embedded in additive manufactured functional structures. In this ITS follow-on paper a thermal model approach and associated predictions are presented, related on the ITS functional breadboards developed at FH Aachen. Predictive TES by PCM is provided by a specially developed ITS PCM subroutine, which is applicable in ESATAN. The subroutine is based on the latent heat storage (LHS) method to numerically embed thermo-physical PCM behavior. Furthermore, a modeling approach is introduced to numerically consider the virtual PCM/lattice nodes within the macro-encapsulated PCM voids of the double wall ITS design. Related on these virtual nodes, in-plane and out-of-plane conductive links are defined. The recent additive manufactured ITS breadboard series are thermally cycled in the thermal vacuum chamber, both with and without embedded PCM. Related on breadboard hardware tests, measurement results are compared with predictions and are subsequently correlated. The results of specific simulations and measurements are presented. Recent predictive results of star tracker analyses are also presented in ICES-2021-106, based on this ITS PCM subroutine.},
  language  = {en}
}
@misc{MayntzKeimerTegtmeyeretal.2021,
  author    = {Mayntz, Joscha and Keimer, Jona and Tegtmeyer, Philipp and Dahmann, Peter and Hille, Sebastian and Stumpf, Eike and Fisher, Alex and Dorrington, Graham},
  title     = {Aerodynamic Investigation on Efficient Inflight Transition of a Propeller from Propulsion to Regeneration Mode},
  series = {AIAA SCITECH 2022 Forum},
  journal   = {AIAA SCITECH 2022 Forum},
  publisher = {AIAA},
  address   = {Reston, Va.},
  doi       = {10.2514/6.2022-0546},
  year      = {2021},
  abstract  = {This paper discusses a new way of inflight power regeneration for electric or hybrid-electric driven general aviation aircraft with one powertrain for both configurations. Three different approaches for the shift from propulsion to regeneration mode are analyzed. Numerical cal-culation and wind tunnel results are compared and show the highest regeneration potential for the "Windmill" approach, where the propeller blades are flipped, and rotation is reversed. A combination of all regeneration approaches for a realistic flight mission is discussed.},
  language  = {en}
}
@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}
}
@article{Maurischat2022,
  author    = {Maurischat, Andreas},
  title     = {Algebraic independence of the Carlitz period and its hyperderivatives},
  series = {Journal of Number Theory},
  volume    = {240},
  journal   = {Journal of Number Theory},
  publisher = {Elsevier},
  address   = {Orlando, Fla.},
  issn      = {0022-314X},
  doi       = {10.1016/j.jnt.2022.01.006},
  pages     = {145 -- 162},
  year      = {2022},
  language  = {en}
}
@incollection{BauschatBennerKlingeetal.2022,
  author    = {Bauschat, J.-Michael and Benner, Miriam and Klinge, Henner and Ziegler, Simon},
  title     = {Urbane Mobilit{\"a}t entdeckt die 3. Dimension},
  series = {Transforming Mobility - What Next?},
  booktitle = {Transforming Mobility - What Next?},
  publisher = {Springer Gabler},
  address   = {Wiesbaden},
  isbn      = {978-3-658-36429-8},
  doi       = {10.1007/978-3-658-36430-4_53},
  pages     = {895 -- 916},
  year      = {2022},
  abstract  = {Der Themenkomplex urbane Mobilit{\"a}t ist getrieben durch den Verkehrsinfarkt in Ballungszentren, durch Luftverschmutzung und L{\"a}rm, sowie den Trend zum Leben in der Stadt in den st{\"a}dteplanerischen Fokus ger{\"u}ckt. Emissionsneutrale Antriebskonzepte in der Luftfahrt f{\"u}hren zu Ans{\"a}tzen Flugger{\"a}te einzusetzen, die batteriegetrieben vertikal aufsteigen und landen k{\"o}nnen. Flugphysikalisch und energetisch ist diese Technik nur dann sinnvoll, wenn es zwingende Gr{\"u}nde gibt (z.B. Rettungseins{\"a}tze), daher wird der flugphysikalische Hintergrund prinzipiell erl{\"a}utert. Es werden einige aktuelle Lufttransportkonzepte f{\"u}r eine urbane Personenbef{\"o}rderung vorgestellt. Sollte es verst{\"a}rkt zu Lufttransport {\"u}ber St{\"a}dten kommen, m{\"u}ssen betroffene Luftr{\"a}ume geordnet und {\"u}berwacht werden. Wie kompatibel Lufttransportsysteme mit den heute bereits relevanten urbanen Bef{\"o}rderungsmitteln sein m{\"u}ssen, wird kritisch diskutiert. Abschließend werden die Aspekte Akzeptanz durch die Kunden und Wirtschaftlichkeit ebenso angerissen, wie die hochproblematische Rohstoffgewinnung, die Entsorgung und das Recycling von Batterien.},
  language  = {de}
}
@article{BergmannGoettenBraunetal.2022,
  author    = {Bergmann, Ole and G{\"o}tten, Falk and Braun, Carsten and Janser, Frank},
  title     = {Comparison and evaluation of blade element methods against RANS simulations and test data},
  series = {CEAS Aeronautical Journal},
  volume    = {13},
  journal   = {CEAS Aeronautical Journal},
  publisher = {Springer},
  address   = {Wien},
  issn      = {1869-5590 (Online)},
  doi       = {10.1007/s13272-022-00579-1},
  pages     = {535 -- 557},
  year      = {2022},
  abstract  = {This paper compares several blade element theory (BET) method-based propeller simulation tools, including an evaluation against static propeller ground tests and high-fidelity Reynolds-Average Navier Stokes (RANS) simulations. Two proprietary propeller geometries for paraglider applications are analysed in static and flight conditions. The RANS simulations are validated with the static test data and used as a reference for comparing the BET in flight conditions. The comparison includes the analysis of varying 2D aerodynamic airfoil parameters and different induced velocity calculation methods. The evaluation of the BET propeller simulation tools shows the strength of the BET tools compared to RANS simulations. The RANS simulations underpredict static experimental data within 10\% relative error, while appropriate BET tools overpredict the RANS results by 15-20\% relative error. A variation in 2D aerodynamic data depicts the need for highly accurate 2D data for accurate BET results. The nonlinear BET coupled with XFOIL for the 2D aerodynamic data matches best with RANS in static operation and flight conditions. The novel BET tool PropCODE combines both approaches and offers further correction models for highly accurate static and flight condition results.},
  language  = {en}
}