TY  - JOUR
A1  - Schopen, Oliver
A1  - Narayan, Sriram
A1  - Beckmann, Marvin
A1  - Najmi, Aezid-Ul-Hassan
A1  - Esch, Thomas
A1  - Shabani, Bahman
T1  - An EIS approach to quantify the effects of inlet air relative humidity on the performance of proton exchange membrane fuel cells: a pathway to developing a novel fault diagnostic method
JF  - International Journal of Hydrogen Energy
N2  - In this work, the effect of low air relative humidity on the operation of a polymer electrolyte membrane fuel cell is investigated. An innovative method through performing in situ electrochemical impedance spectroscopy is utilised to quantify the effect of inlet air relative humidity at the cathode side on internal ionic resistances and output voltage of the fuel cell. In addition, algorithms are developed to analyse the electrochemical characteristics of the fuel cell. For the specific fuel cell stack used in this study, the membrane resistance drops by over 39 % and the cathode side charge transfer resistance decreases by 23 % after increasing the humidity from 30 % to 85 %, while the results of static operation also show an increase of ∼2.2 % in the voltage output after increasing the relative humidity from 30 % to 85 %. In dynamic operation, visible drying effects occur at < 50 % relative humidity, whereby the increase of the air side stoichiometry increases the drying effects. Furthermore, other parameters, such as hydrogen humidification, internal stack structure, and operating parameters like stoichiometry, pressure, and temperature affect the overall water balance. Therefore, the optimal humidification range must be determined by considering all these parameters to maximise the fuel cell performance and durability. The results of this study are used to develop a health management system to ensure sufficient humidification by continuously monitoring the fuel cell polarisation data and electrochemical impedance spectroscopy indicators.
KW  - PEM fuel cell
KW  - Electrochemical impedance spectroscopy
KW  - Relative air humidity
KW  - Active humidity control
KW  - Impedance analysis
Y1  - 2024
SN  - 0360-3199 (print)
U6  - https://doi.org/10.1016/j.ijhydene.2024.01.218
SN  - 1879-3487 (online)
VL  - 58
IS  - 8
SP  - 1302
EP  - 1315
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Stark, Ralf
A1  - Rieping, Carla
A1  - Esch, Thomas
T1  - The impact of guide tubes on flow separation in rocket nozzles
T2  - Aerospace Europe Conference 2023 - 10th EUCASS - 9th CEAS
N2  - Rocket engine test facilities and launch pads are typically equipped with a guide tube. Its purpose is to ensure the controlled and safe routing of the hot exhaust gases. In addition, the guide tube induces a suction that effects the nozzle flow, namely the flow separation during transient start-up and shut-down of the engine. A cold flow subscale nozzle in combination with a set of guide tubes was studied experimentally
to determine the main influencing parameters.
KW  - Guide Tube
KW  - TICTOP
KW  - Nozzle
KW  - Suction
Y1  - 2023
N1  - Lausanne, July 9-13, 2023
ER  - 
TY  - JOUR
A1  - Seifarth, Volker
A1  - Goßmann, Matthias
A1  - Grosse, J. O.
A1  - Becker, C.
A1  - Heschel, I.
A1  - Artmann, Gerhard
A1  - Temiz Artmann, Aysegül
T1  - Development of a Bioreactor to Culture Tissue Engineered Ureters Based on the Application of Tubular OPTIMAIX 3D Scaffolds
JF  - Urologia Internationalis
Y1  - 2015
U6  - https://doi.org/10.1159/000368419
SN  - 0042-1138
VL  - 2015
IS  - 95
SP  - 106
EP  - 113
PB  - Karger
CY  - Basel
ER  - 
TY  - CHAP
A1  - Britten, G.
A1  - Braun, Carsten
A1  - Hesse, M.
A1  - Ballmann, Josef
T1  - Computational aeroelasticity with reduced structural models
T2  - Flow modulation and fluid-structure interaction at airplane wings : research results of the Collaborative Research Center SFB 401 at RWTH Aachen, University of Technology, Aachen, Germany / Josef Ballmann (Ed.) Notes on numerical fluid mechanics and multidisciplinary design. Vol. 84
Y1  - 2003
SN  - 3-540-40209-8
SP  - 275
EP  - 299
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Dickhoff, Jens
A1  - Horikawa, Atsushi
A1  - Funke, Harald
T1  - Hydrogen Combustion - new DLE Combustor Addresses NOx Emissions and Flashback
JF  - Turbomachinery international : the global journal of energy equipment
Y1  - 2021
SN  - 2767-2328
SN  - 0149-4147
VL  - 62
IS  - 4
SP  - 26
EP  - 27
PB  - MJH Life Sciences
CY  - Cranbury
ER  - 
TY  - CHAP
A1  - Horikawa, Atsushi
A1  - Ashikaga, Mitsugu
A1  - Yamaguchi, Masato
A1  - Ogino, Tomoyuki
A1  - Aoki, Shigeki
A1  - Wirsum, Manfred
A1  - Funke, Harald
A1  - Kusterer, Karsten
T1  - Combined heat and power supply demonstration of Micro-Mix Hydrogen Combustion Applied to M1A-17 Gas Turbine
T2  - Proceedings of ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition (GT2022) (Volume 3A)
N2  - Kawasaki Heavy Industries, Ltd. (KHI), Aachen University of Applied Sciences, and B&B-AGEMA GmbH have investigated the potential of low NOx micro-mix (MMX) hydrogen combustion and its application to an industrial gas turbine combustor. Engine demonstration tests of a MMX combustor for the M1A-17 gas turbine with a co-generation system were conducted in the hydrogen-fueled power generation plant in Kobe City, Japan.
This paper presents the results of the commissioning test and the combined heat and power (CHP) supply demonstration. In the commissioning test, grid interconnection, loading tests and load cut-off tests were successfully conducted. All measurement results satisfied the Japanese environmental regulation values. Dust and soot as well as SOx were not detected. The NOx emissions were below 84 ppmv at 15 % O2. The noise level at the site boundary was below 60 dB. The vibration at the site boundary was below 45 dB.
During the combined heat and power supply demonstration, heat and power were supplied to neighboring public facilities with the MMX combustion technology and 100 % hydrogen fuel. The electric power output reached 1800 kW at which the NOx emissions were 72 ppmv at 15 % O2, and 60 %RH. Combustion instabilities were not observed. The gas turbine efficiency was improved by about 1 % compared to a non-premixed type combustor with water injection as NOx reduction method. During a total equivalent operation time of 1040 hours, all combustor parts, the M1A-17 gas turbine as such, and the co-generation system were without any issues.
KW  - industrial gas turbine
KW  - combustor development
KW  - fuels
KW  - hydrogen
KW  - emission
Y1  - 2022
SN  - 978-0-7918-8599-4
U6  - https://doi.org/10.1115/GT2022-81620
N1  - ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition
June 13–17, 2022 Rotterdam, Netherlands
PB  - American Society of Mechanical Engineers
CY  - Fairfield
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, Wolfgang
A1  - Lämmerzahl, W.
T1  - Solar Sail Propulsion: An Enabling Technology for Fundamental Physics Missions
JF  - Lasers, Clocks and Drag Free Control : Exploration of Relativistic Gravity in Space / by Hansjörg Dittus ..., eds. - ( Astrophysics and Space Science Library ; 349)
Y1  - 2008
SN  - 978-3-540-34376-9
SP  - 379
EP  - 398
PB  - Springer
CY  - Berlin [u.a.]
ER  - 
TY  - CHAP
A1  - Grundmann, Jan Thimo
A1  - Bauer, Waldemar
A1  - Borchers, Kai
A1  - Dumont, Etienne
A1  - Grimm, Christian D.
A1  - Ho, Tra-Mi
A1  - Jahnke, Rico
A1  - Lange, Caroline
A1  - Maiwald, Volker
A1  - Mikulz, Eugen
A1  - Quantius, Dominik
A1  - Reershemius, Siebo
A1  - Renger, Thomas
A1  - Riemann, Johannes
A1  - Sasaki, Kaname
A1  - Seefeldt, Patric
A1  - Spietz, Peter
A1  - Spröwitz, Tom
A1  - Toth, Norbert
A1  - Wejmo, Elisabet
A1  - Biele, Jens
A1  - Krause, Christian
A1  - Cerotti, Matteo
A1  - Peloni, Alessandro
A1  - Dachwald, Bernd
T1  - Small Spacecraft Solar Sailing for Small Solar System Body Multiple Rendezvous and Landing
T2  - 2018 IEEE Aerospace Conference : 3-10 March 2018
Y1  - 2018
SN  - 978-1-5386-2014-4
ER  - 
TY  - JOUR
A1  - Jan Thimo, Grundmann
A1  - Bauer, Waldemar
A1  - Biele, Jens
A1  - Boden, Ralf
A1  - Ceriotti, Matteo
A1  - Cordero, Federico
A1  - Dachwald, Bernd
A1  - Dumont, Etienne
A1  - Grimm, Christian D.
A1  - Hercik, David
T1  - Capabilities of Gossamer-1 derived small spacecraft solar sails carrying Mascot-derived nanolanders for in-situ surveying of NEAs
JF  - Acta Astronautica
Y1  - 2019
U6  - https://doi.org/10.1016/j.actaastro.2018.03.019
SN  - 0094-5765
VL  - 156
IS  - 3
SP  - 330
EP  - 362
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Gierse, Andreas
A1  - Krämer, Stefan
A1  - Daab, Dominique J.
A1  - Hessel, Joana
A1  - Baader, Fabian
A1  - Müller, Brigitte S.
A1  - Wagner, Tobias
A1  - Gdalewitsch, Georg
A1  - Plescher, Engelbert
A1  - Pfützenreuter, Lysan
T1  - Experimental in-flight modal-analysis of a sounding rocket structure
T2  - 21st ESA Symposium on Rocket and Ballon related Research
Y1  - 2013
SN  - 9789290922858
SP  - 341
EP  - 346
ER  -