TY  - GEN
A1  - Machado, Patricia Almeida
A1  - Dahmann, Peter
A1  - Keimer, Jona
A1  - Saretzki, Charlotte
A1  - Stübing, Felix
A1  - Küpper, Thomas
T1  - Stress profile and individual workload monitoring in general aviation pilots – an experiment’s setting
T2  - 23. Annual Meeting of the German Society of Travel Medicine, Coburg, 18.-19.9.2020
Y1  - 2020
U6  - https://doi.org/10.55225/hppa.156
ER  - 
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  - CHAP
A1  - Stark, Ralf
A1  - Bartel, Sebastian
A1  - Ditsche, Florian
A1  - Esch, Thomas
T1  - Design study of a 30kN LOX/LCH4 aerospike rocket engine for lunar lander application
T2  - Aerospace Europe Conference 2023 - 10th EUCASS - 9th CEAS
N2  - Based on lunar lander concept EL3, various LOX/CH4 aerospike engines were studied. A distinction was made between single and cluster configurations as well as ideal and non-ideal contour concepts. It could be shown that non-ideal aerospike engines promise a significant payload gain.
Y1  - 2023
N1  - Lausanne, July 9-13, 2023
ER  - 
TY  - CHAP
A1  - Altherr, Lena
A1  - Döring, Bernd
A1  - Frauenrath, Tobias
A1  - Groß, Rolf
A1  - Mohan, Nijanthan
A1  - Oyen, Marc
A1  - Schnittcher, Lukas
A1  - Voß, Norbert
ED  - Reiff-Stephan, Jörg
ED  - Jäkel, Jens
ED  - Schwarz, André
T1  - DiggiTwin: ein interdisziplinäres Projekt zur Nutzung digitaler Zwillinge auf dem Weg zu einem klimaneutralen Gebäudebestand
T2  - Tagungsband AALE 2024 : Fit für die Zukunft: praktische Lösungen für die industrielle Automation
N2  - Im Hinblick auf die Klimaziele der Bundesrepublik Deutschland konzentriert sich das Projekt Diggi Twin auf die nachhaltige Gebäudeoptimierung. Grundlage für eine ganzheitliche Gebäudeüberwachung und -optimierung bildet dabei die Digitalisierung und Automation im Sinne eines Smart Buildings. Das interdisziplinäre Projekt der FH Aachen hat das Ziel, ein bestehendes Hochschulgebäude und einen Neubau an klimaneutrale Standards anzupassen. Im Rahmen des Projekts werden bekannte Verfahren, wie das Building Information Modeling (BIM), so erweitert, dass ein digitaler Gebäudezwilling entsteht. Dieser kann zur Optimierung des Gebäudebetriebs herangezogen werden, sowie als Basis für eine Erweiterung des Bewertungssystems Nachhaltiges Bauen (BNB) dienen. Mithilfe von Sensortechnologie und künstlicher Intelligenz kann so ein präzises Monitoring wichtiger Gebäudedaten erfolgen, um ungenutzte Energieeinsparpotenziale zu erkennen und zu nutzen. Das Projekt erforscht und setzt methodische Erkenntnisse zu BIM und digitalen Gebäudezwillingen praxisnah um, indem es spezifische Fragen zur Energie- und Ressourceneffizienz von Gebäuden untersucht und konkrete Lösungen für die Gebäudeoptimierung entwickelt.
KW  - Anomalieerkennung
KW  - IoT
KW  - Überwachung & Optimierung
KW  - DiggiTwin
KW  - BIM
KW  - Smart Building
KW  - Digitalisierung
Y1  - 2024
SN  - 978-3-910103-02-3
U6  - https://doi.org/10.33968/2024.67
N1  - 20. AALE-Konferenz. Bielefeld, 06.03.-08.03.2024
(Tagungsband unter https://doi.org/10.33968/2024.29)
SP  - 341
EP  - 346
PB  - le-tex publishing services GmbH
CY  - Leipzig
ER  - 
TY  - CHAP
A1  - Duran Paredes, Ludwin
A1  - Mottaghy, Darius
A1  - Herrmann, Ulf
A1  - Groß, Rolf Fritz
T1  - Online ground temperature and soil moisture monitoring of a shallow geothermal system with non-conventional components
T2  - EGU General Assembly 2020
N2  - We present first results from a newly developed monitoring station for a closed loop geothermal heat pump test installation at our campus, consisting of helix coils and plate heat exchangers, as well as an ice-store system. There are more than 40 temperature sensors and several soil moisture content sensors distributed around the system, allowing a detailed monitoring under different operating conditions.In the view of the modern development of renewable energies along with the newly concepts known as Internet of Things and Industry 4.0 (high-tech strategy from the German government), we created a user-friendly web application, which will connect the things (sensors) with the open network (www). Besides other advantages, this allows a continuous remote monitoring of the data from the numerous sensors at an arbitrary sampling rate.Based on the recorded data, we will also present first results from numerical simulations, taking into account all relevant heat transport processes.The aim is to improve the understanding of these processes and their influence on the thermal behavior of shallow geothermal systems in the unsaturated zone. This will in turn facilitate the prediction of the performance of these systems and therefore yield an improvement in their dimensioning when designing a specific shallow geothermal installation.
Y1  - 2020
N1  - EGU General Assembly 2020, Online, 4–8 May 2020
ER  - 
TY  - JOUR
A1  - Fayyazi, Mojgan
A1  - Sardar, Paramjotsingh
A1  - Thomas, Sumit Infent
A1  - Daghigh, Roonak
A1  - Jamali, Ali
A1  - Esch, Thomas
A1  - Kemper, Hans
A1  - Langari, Reza
A1  - Khayyam, Hamid
T1  - Artificial intelligence/machine learning in energy management systems, control, and optimization of hydrogen fuel cell vehicles
N2  - 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.
KW  - optimization system
KW  - intelligent control
KW  - fuel cell vehicle
KW  - machine learning
KW  - artificial intelligence
KW  - intelligent energy management
Y1  - 2023
U6  - https://doi.org/10.3390/su15065249
N1  - This article belongs to the Special Issue "Circular Economy and Artificial Intelligence"
VL  - 15
IS  - 6
SP  - 38
PB  - MDPI
CY  - Basel
ER  - 
TY  - CHAP
A1  - Veettil, Yadu Krishna Morassery
A1  - Rakshit, Shantam
A1  - Schopen, Oliver
A1  - Kemper, Hans
A1  - Esch, Thomas
A1  - Shabani, Bahman
ED  - Bin Abdollah, Mohd Fadzli
ED  - Amiruddin, Hilmi
ED  - Singh, Amrik Singh Phuman
ED  - Munir, Fudhail Abdul
ED  - Ibrahim, Asriana
T1  - Automated Control System Strategies to Ensure Safety of PEM Fuel Cells Using Kalman Filters
T2  - Proceedings of the 7th International Conference and Exhibition on Sustainable Energy and Advanced Materials (ICE-SEAM 2021), Melaka, Malaysia
N2  - Having well-defined control strategies for fuel cells, that can efficiently detect errors and take corrective action is critically important for safety in all applications, and especially so in aviation. The algorithms not only ensure operator safety by monitoring the fuel cell and connected components, but also contribute to extending the health of the fuel cell, its durability and safe operation over its lifetime. While sensors are used to provide peripheral data surrounding the fuel cell, the internal states of the fuel cell cannot be directly measured. To overcome this restriction, Kalman Filter has been implemented as an internal state observer.
Other safety conditions are evaluated using real-time data from every connected sensor and corrective actions automatically take place to ensure safety. The algorithms discussed in this paper have been validated thorough Model-in-the-Loop (MiL) tests as well as practical validation at a dedicated test bench.
KW  - control system
KW  - PEM fuel cells
KW  - Kalman filter
Y1  - 2022
SN  - 978-981-19-3178-9
SN  - 978-981-19-3179-6 (E-Book)
U6  - https://doi.org/10.1007/978-981-19-3179-6_55
SN  - 2195-4356
N1  - 7th International Conference and Exhibition on Sustainable Energy and Advanced Material (ICE-SEAM 2021), Universiti Teknikal Malaysia Melaka (UTeM), Malaysia, in association with the Universitas Sebelas Maret (UNS), Indonesia, 23 November 2021
SP  - 296
EP  - 299
PB  - Springer Nature
CY  - Singapore
ER  - 
TY  - CHAP
A1  - Sattler, Johannes Christoph
A1  - Atti, Vikrama
A1  - Alexopoulos, Spiros
A1  - Teixeira Boura, Cristiano José
A1  - Herrmann, Ulf
A1  - Dutta, Siddharth
A1  - Kioutsioukis, Ioannis
T1  - DNI forecast tool for the smart operation of a parabolic trough collector system with concrete thermal energy storage: Theory, results and outlook
T2  - SolarPACES 2022 conference proceedings
N2  - This work presents a basic forecast tool for predicting direct normal irradiance (DNI) in hourly resolution, which the Solar-Institut Jülich (SIJ) is developing within a research project. The DNI forecast data shall be used for a parabolic trough collector (PTC) system with a concrete thermal energy storage (C-TES) located at the company KEAN Soft Drinks Ltd in Limassol, Cyprus. On a daily basis, 24-hour DNI prediction data in hourly resolution shall be automatically produced using free or very low-cost weather forecast data as input. The purpose of the DNI forecast tool is to automatically transfer the DNI forecast data on a daily basis to a main control unit (MCU). The MCU automatically makes a smart decision on the operation mode of the PTC system such as steam production mode and/or C-TES charging mode. The DNI forecast tool was evaluated using historical data of measured DNI from an on-site weather station, which was compared to the DNI forecast data. The DNI forecast tool was tested using data from 56 days between January and March 2022, which included days with a strong variation in DNI due to cloud passages. For the evaluation of the DNI forecast reliability, three categories were created and the forecast data was sorted accordingly. The result was that the DNI forecast tool has a reliability of 71.4 % based on the tested days. The result fulfils SIJ’s aim to achieve a reliability of around 70 %, but SIJ aims to still improve the DNI forecast quality.
KW  - Direct normal irradiance forecast
KW  - DNI forecast
KW  - Parabolic trough collector
KW  - PTC
KW  - Thermal Energy Storage
Y1  - 2024
U6  - https://doi.org/10.52825/solarpaces.v1i.731
SN  - 2751-9899 (online)
N1  - SolarPACES 2022, 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA
IS  - 1
PB  - TIB Open Publishing
CY  - Hannover
ER  - 
TY  - CHAP
A1  - Schopen, Oliver
A1  - Kemper, Hans
A1  - Esch, Thomas
T1  - Development of a comparison methodology and evaluation matrix for electrically driven compressors in ICE and FC
T2  - Proceedings of the 1st UNITED – Southeast Asia Automotive Interest Group (SAIG) International Conference
N2  - 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.
KW  - electro mobility
KW  - fuel cell
KW  - internal combustion engine
KW  - electrically driven compressors
Y1  - 2021
SN  - 978-3-902103-94-9
N1  - 1st UNITED-SAIG International Conference, 21-22 APR 2021, Chulalongkorn University, Thailand
SP  - 45
EP  - 46
PB  - FH Joanneum
CY  - Graz
ER  - 
TY  - CHAP
A1  - Haugg, Albert Thomas
A1  - Kreyer, Jörg
A1  - Kemper, Hans
A1  - Hatesuer, Katerina
A1  - Esch, Thomas
T1  - Heat exchanger for ORC. adaptability and optimisation potentials
T2  - IIR International Rankine 2020 Conference
N2  - The recovery of waste heat requires heat exchangers to extract it from a liquid or gaseous medium into another working medium, a refrigerant. In Organic Rankine Cycles (ORC) on Combustion Engines there are two major heat sources, the exhaust gas and the water/glycol fluid from the engine’s cooling circuit. A heat exchanger design must be adapted to the different requirements and conditions resulting from the heat sources, fluids, system configurations, geometric restrictions, and etcetera. The Stacked Shell Cooler (SSC) is a new and very specific design of a plate heat exchanger, created by AKG, which allows with a maximum degree of freedom the optimization of heat exchange rate and the reduction of the related pressure drop. This optimization in heat exchanger design for ORC systems is even more important, because it reduces the energy consumption of the system and therefore maximizes the increase in overall efficiency of the engine.
Y1  - 2020
U6  - https://doi.org/10.18462/iir.rankine.2020.1224
N1  - IIR International Rankine 2020 Conference - Heating, Cooling, Power Generation. Glasgow, 2020.
ER  - 
TY  - CHAP
A1  - Schopen, Oliver
A1  - Shabani, Bahman
A1  - Esch, Thomas
A1  - Kemper, Hans
A1  - Shah, Neel
ED  - Rahim, S.A.
ED  - As'arry, A.
ED  - Zuhri, M.Y.M.
ED  - Harmin, M.Y.
ED  - Rezali, K.A.M.
ED  - Hairuddin, A.A.
T1  - Quantitative evaluation of health management designs for fuel cell systems in transport vehicles
T2  - 2nd UNITED-SAIG International Conference Proceedings
N2  - Focusing on transport vehicles, mainly with regard to aviation applications, this paper presents compilation and subsequent quantitative evaluation of methods aimed at building an optimum integrated health management solution for fuel cell systems. The methods are divided into two different main types and compiled in a related scheme. Furthermore, different methods are analysed and evaluated based on parameters specific to the aviation context of this study. Finally, the most suitable method for use in fuel cell health management systems is identified and its performance and suitability is quantified.
KW  - aviation application
KW  - health management systems
KW  - fuel cell systems
Y1  - 2022
N1  - 2nd UNITED-SAIG International Conference, 23-24 May 2022, Putrajaya, Malaysia
SP  - 1
EP  - 3
ER  - 
TY  - RPRT
A1  - Hebel, Christoph
A1  - Merkens, Torsten
A1  - Feyerl, Günter
A1  - Kemper, Hans
A1  - Busse, Daniel
T1  - Elektromobilität - Verbundprojekt "COSTARTebus": Comprehensive strategy to accelerate the integration of electric-buses into existing public transport systems - Teilprojekt A : Berichtszeitraum: 01.01.2018-31.10.2020
Y1  - 2021
N1  - Förderkennzeichen BMVI 03EMEN10A
Verbundnummer 01182550
PB  - Fachhochschule Aachen
CY  - Aachen
ER  -