@inproceedings{ZahraPhaniSrujanChicoCaminosetal.2022,
  author    = {Zahra, Mahdi and Phani Srujan, Merige and Chico Caminos, Ricardo Alexander and Schmitz, Pascal and Herrmann, Ulf and Teixeira Boura, Cristiano Jos{\´e} and Schmitz, Mark and Gielen, Hans and Gedle, Yibekal and Dersch, J{\"u}rgen},
  title     = {Modeling the thermal behavior of solar salt in electrical resistance heaters for the application in PV-CSP hybrid power plants},
  series = {SOLARPACES 2020},
  booktitle = {SOLARPACES 2020},
  number    = {2445 / 1},
  publisher = {AIP conference proceedings / American Institute of Physics},
  address   = {Melville, NY},
  isbn      = {978-0-7354-4195-8},
  issn      = {1551-7616 (online)},
  doi       = {10.1063/5.0086268},
  pages     = {9 Seiten},
  year      = {2022},
  abstract  = {Concentrated Solar Power (CSP) systems are able to store energy cost-effectively in their integrated thermal energy storage (TES). By intelligently combining Photovoltaics (PV) systems with CSP, a further cost reduction of solar power plants is expected, as well as an increase in dispatchability and flexibility of power generation. PV-powered Resistance Heaters (RH) can be deployed to raise the temperature of the molten salt hot storage from 385 °C up to 565 °C in a Parabolic Trough Collector (PTC) plant. To avoid freezing and decomposition of molten salt, the temperature distribution in the electrical resistance heater is investigated in the present study. For this purpose, a RH has been modeled and CFD simulations have been performed. The simulation results show that the hottest regions occur on the electric rod surface behind the last baffle. A technical optimization was performed by adjusting three parameters: Shell-baffle clearance, electric rod-baffle clearance and number of baffles. After the technical optimization was carried out, the temperature difference between the maximum temperature and the average outlet temperature of the salt is within the acceptable limits, thus critical salt decomposition has been avoided. Additionally, the CFD simulations results were analyzed and compared with results obtained with a one-dimensional model in Modelica.},
  language  = {en}
}
@incollection{WeberBomholtButenweg2022,
  author    = {Weber, Felix and Bomholt, Frederik and Butenweg, Christoph},
  title     = {Erdbeben- und Schwingungsschutz von Bauwerken},
  series = {2023 BetonKalender: Wasserundurchl{\"a}ssiger Beton, Br{\"u}ckenbau},
  booktitle = {2023 BetonKalender: Wasserundurchl{\"a}ssiger Beton, Br{\"u}ckenbau},
  editor    = {Bergmeister, Konrad and Fingerloos, Frank and W{\"o}rner, Johann-Dietrich},
  publisher = {Ernst \& Sohn},
  address   = {Berlin},
  isbn      = {9783433611180},
  doi       = {10.1002/9783433611180.ch16},
  pages     = {779 -- 859},
  year      = {2022},
  abstract  = {Dieser Beitrag beschreibt die herk{\"o}mmlichen Maßnahmen wie die Kapazit{\"a}tsbemessung der Tragwerksstruktur, die Isolation des Bauwerks mittels Basisisolatoren, die D{\"a}mpfungserh{\"o}hung der Struktur mittels Inter-Story-D{\"a}mpfern und die Schwingungsreduktion mittels Schwingungstilgern gegen Einwirkungen durch Erdbeben, Wind, Verkehr und Personen auf die Bauwerke. Erg{\"a}nzend wird die erdbebengerechte Auslegung und Isolation von nichttragenden Bauteilen behandelt. F{\"u}r die betrachteten Systeme werden die Bewegungsdifferenzialgleichungen unter Ber{\"u}cksichtigung der wesentlichen Nichtlinearit{\"a}ten angegeben. Die vorgestellten Weiterentwicklungen in den Bereichen der Basisisolatoren, D{\"a}mpfern und Schwingungstilgern zeigen, dass das modellbasierte Design mittels Simulation ein sehr effektives, {\"o}konomisches und dank der heutigen Computerleistung auch zeiteffizientes Werkzeug darstellt.},
  language  = {de}
}
@incollection{StriebingMuellerSchraudneretal.2022,
  author    = {Striebing, Clemens and M{\"u}ller, J{\"o}rg and Schraudner, Martina and Gewinner, Irina Valerie and Guerrero Morales, Patricia and Hochfeld, Katharina and Hoffman, Shekinah and Kmec, Julie A. and Nguyen, Huu Minh and Schneider, Jannick and Sheridan, Jennifer and Steuer-Dankert, Linda and Trimble O'Connor, Lindsey and Vandevelde-Rougale, Agn{\`e}s},
  title     = {Promoting diversity and combatting discrimination in research organizations: a practitioner's guide},
  series = {Diversity and discrimination in research organizations},
  booktitle = {Diversity and discrimination in research organizations},
  publisher = {Emerald Publishing Limited},
  address   = {Bingley},
  isbn      = {978-1-80117-959-1 (Print)},
  doi       = {10.1108/978-1-80117-956-020221012},
  pages     = {421 -- 442},
  year      = {2022},
  abstract  = {The essay is addressed to practitioners in research management and from academic leadership. It describes which measures can contribute to creating an inclusive climate for research teams and preventing and effectively dealing with discrimination. The practical recommendations consider the policy and organizational levels, as well as the individual perspective of research managers. Following a series of basic recommendations, six lessons learned are formulated, derived from the contributions to the edited collection on "Diversity and Discrimination in Research Organizations."},
  language  = {en}
}
@incollection{SteuerDankertLeichtScholten2022,
  author    = {Steuer-Dankert, Linda and Leicht-Scholten, Carmen},
  title     = {Perceiving diversity : an explorative approach in a complex research organization.},
  series = {Diversity and discrimination in research organizations},
  booktitle = {Diversity and discrimination in research organizations},
  publisher = {Emerald Publishing Limited},
  address   = {Bingley},
  isbn      = {978-1-80117-959-1 (Print)},
  doi       = {10.1108/978-1-80117-956-020221010},
  pages     = {365 -- 392},
  year      = {2022},
  abstract  = {Diversity management is seen as a decisive factor for ensuring the development of socially responsible innovations (Beacham and Shambaugh, 2011; Sonntag, 2014; L{\´o}pez, 2015; Uebernickel et al., 2015). However, many diversity management approaches fail due to a one-sided consideration of diversity (Thomas and Ely, 2019) and a lacking linkage between the prevailing organizational culture and the perception of diversity in the respective organization. Reflecting the importance of diverse perspectives, research institutions have a special responsibility to actively deal with diversity, as they are publicly funded institutions that drive socially relevant development and educate future generations of developers, leaders and decision-makers. Nevertheless, only a few studies have so far dealt with the influence of the special framework conditions of the science system on diversity management. Focusing on the interdependency of the organizational culture and diversity management especially in a university research environment, this chapter aims in a first step to provide a theoretical perspective on the framework conditions of a complex research organization in Germany in order to understand the system-specific factors influencing diversity management. In a second step, an exploratory cluster analysis is presented, investigating the perception of diversity and possible influencing factors moderating this perception in a scientific organization. Combining both steps, the results show specific mechanisms and structures of the university research environment that have an impact on diversity management and rigidify structural barriers preventing an increase of diversity. The quantitative study also points out that the management level takes on a special role model function in the scientific system and thus has an influence on the perception of diversity. Consequently, when developing diversity management approaches in research organizations, it is necessary to consider the top-down direction of action, the special nature of organizational structures in the university research environment as well as the special role of the professorial level as role model for the scientific staff.},
  language  = {en}
}
@article{SchwagerFleschSchwarzboezletal.2022,
  author    = {Schwager, Christian and Flesch, Robert and Schwarzb{\"o}zl, Peter and Herrmann, Ulf and Teixeira Boura, Cristiano Jos{\´e}},
  title     = {Advanced two phase flow model for transient molten salt receiver system simulation},
  series = {Solar Energy},
  volume    = {232},
  journal   = {Solar Energy},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0038-092X (print)},
  doi       = {10.1016/j.solener.2021.12.065},
  pages     = {362 -- 375},
  year      = {2022},
  abstract  = {In order to realistically predict and optimize the actual performance of a concentrating solar power (CSP) plant sophisticated simulation models and methods are required. This paper presents a detailed dynamic simulation model for a Molten Salt Solar Tower (MST) system, which is capable of simulating transient operation including detailed startup and shutdown procedures including drainage and refill. For appropriate representation of the transient behavior of the receiver as well as replication of local bulk and surface temperatures a discretized receiver model based on a novel homogeneous two-phase (2P) flow modelling approach is implemented in Modelica Dymola®. This allows for reasonable representation of the very different hydraulic and thermal properties of molten salt versus air as well as the transition between both. This dynamic 2P receiver model is embedded in a comprehensive one-dimensional model of a commercial scale MST system and coupled with a transient receiver flux density distribution from raytracing based heliostat field simulation. This enables for detailed process prediction with reasonable computational effort, while providing data such as local salt film and wall temperatures, realistic control behavior as well as net performance of the overall system. Besides a model description, this paper presents some results of a validation as well as the simulation of a complete startup procedure. Finally, a study on numerical simulation performance and grid dependencies is presented and discussed.},
  language  = {en}
}
@inproceedings{SchwagerAngeleNourietal.2022,
  author    = {Schwager, Christian and Angele, Florian and Nouri, Bijan and Schwarzb{\"o}zl, Peter and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf},
  title     = {Impact of DNI forecast quality on performance prediction for a commercial scale solar tower: Application of nowcasting DNI maps to dynamic solar tower simulation},
  series = {SolarPACES 2022 conference proceedings},
  booktitle = {SolarPACES 2022 conference proceedings},
  number    = {1},
  publisher = {TIB Open Publishing},
  address   = {Hannover},
  issn      = {2751-9899 (online)},
  doi       = {10.52825/solarpaces.v1i.675},
  pages     = {9 Seiten},
  year      = {2022},
  abstract  = {Concerning current efforts to improve operational efficiency and to lower overall costs of concentrating solar power (CSP) plants with prediction-based algorithms, this study investigates the quality and uncertainty of nowcasting data regarding the implications for process predictions. DNI (direct normal irradiation) maps from an all-sky imager-based nowcasting system are applied to a dynamic prediction model coupled with ray tracing. The results underline the need for high-resolution DNI maps in order to predict net yield and receiver outlet temperature realistically. Furthermore, based on a statistical uncertainty analysis, a correlation is developed, which allows for predicting the uncertainty of the net power prediction based on the corresponding DNI forecast uncertainty. However, the study reveals significant prediction errors and the demand for further improvement in the accuracy at which local shadings are forecasted.},
  language  = {en}
}
@inproceedings{SchulteSchwagerFrantzetal.2022,
  author    = {Schulte, Jonas and Schwager, Christian and Frantz, Cathy and Schloms, Felix and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf},
  title     = {Control concept for a molten salt receiver in star design: Development, optimization and testing with cloud passage scenarios},
  series = {SolarPACES 2022 conference proceedings},
  booktitle = {SolarPACES 2022 conference proceedings},
  number    = {1},
  publisher = {TIB Open Publishing},
  address   = {Hannover},
  issn      = {2751-9899 (online)},
  doi       = {10.52825/solarpaces.v1i.693},
  pages     = {9 Seiten},
  year      = {2022},
  abstract  = {A promising approach to reduce the system costs of molten salt solar receivers is to enable the irradiation of the absorber tubes on both sides. The star design is an innovative receiver design, pursuing this approach. The unconventional design leads to new challenges in controlling the system. This paper presents a control concept for a molten salt receiver system in star design. The control parameters are optimized in a defined test cycle by minimizing a cost function. The control concept is tested in realistic cloud passage scenarios based on real weather data. During these tests, the control system showed no sign of unstable behavior, but to perform sufficiently in every scenario further research and development like integrating Model Predictive Controls (MPCs) need to be done. The presented concept is a starting point to do so.},
  language  = {en}
}
@inproceedings{SattlerSchneiderAngeleetal.2022,
  author    = {Sattler, Johannes Christoph and Schneider, Iesse Peer and Angele, Florian and Atti, Vikrama Naga Babu and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf},
  title     = {Development of heliostat field calibration methods: Theory and experimental test results},
  series = {SolarPACES 2022 conference proceedings},
  booktitle = {SolarPACES 2022 conference proceedings},
  number    = {1},
  publisher = {TIB Open Publishing},
  address   = {Hannover},
  issn      = {2751-9899 (online)},
  doi       = {10.52825/solarpaces.v1i.678},
  pages     = {9 Seiten},
  year      = {2022},
  abstract  = {In this work, three patent pending calibration methods for heliostat fields of central receiver systems (CRS) developed by the Solar-Institut J{\"u}lich (SIJ) of the FH Aachen University of Applied Sciences are presented. The calibration methods can either operate in a combined mode or in stand-alone mode. The first calibration method, method A, foresees that a camera matrix is placed into the receiver plane where it is subjected to concentrated solar irradiance during a measurement process. The second calibration method, method B, uses an unmanned aerial vehicle (UAV) such as a quadrocopter to automatically fly into the reflected solar irradiance cross-section of one or more heliostats (two variants of method B were tested). The third calibration method, method C, foresees a stereo central camera or multiple stereo cameras installed e.g. on the solar tower whereby the orientations of the heliostats are calculated from the location detection of spherical red markers attached to the heliostats. The most accurate method is method A which has a mean accuracy of 0.17 mrad. The mean accuracy of method B variant 1 is 1.36 mrad and of variant 2 is 1.73 mrad. Method C has a mean accuracy of 15.07 mrad. For method B there is great potential regarding improving the measurement accuracy. For method C the collected data was not sufficient for determining whether or not there is potential for improving the accuracy.},
  language  = {en}
}
@inproceedings{SattlerAttiAlexopoulosetal.2022,
  author    = {Sattler, Johannes Christoph and Atti, Vikrama Naga Babu and Alexopoulos, Spiros and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf and Dutta, Siddharth and Kioutsioukis, Ioannis},
  title     = {DNI forecast tool for the smart operation of a parabolic trough collector system with concrete thermal energy storage: Theory, results and outlook},
  series = {SolarPACES 2022 conference proceedings},
  booktitle = {SolarPACES 2022 conference proceedings},
  number    = {1},
  publisher = {TIB Open Publishing},
  address   = {Hannover},
  issn      = {2751-9899 (online)},
  doi       = {10.52825/solarpaces.v1i.731},
  pages     = {9 Seiten},
  year      = {2022},
  abstract  = {This work presents a basic forecast tool for predicting direct normal irradiance (DNI) in hourly resolution, which the Solar-Institut J{\"u}lich (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.},
  language  = {en}
}
@article{RossiWinandsButenweg2022,
  author    = {Rossi, Leonardo and Winands, Mark H. M. and Butenweg, Christoph},
  title     = {Monte Carlo Tree Search as an intelligent search tool in structural design problems},
  series = {Engineering with Computers : An International Journal for Simulation-Based Engineering},
  volume    = {38},
  journal   = {Engineering with Computers : An International Journal for Simulation-Based Engineering},
  number    = {4},
  editor    = {Zhang, Jessica},
  publisher = {Springer Nature},
  address   = {Cham},
  issn      = {1435-5663},
  doi       = {10.1007/s00366-021-01338-2},
  pages     = {3219 -- 3236},
  year      = {2022},
  abstract  = {Monte Carlo Tree Search (MCTS) is a search technique that in the last decade emerged as a major breakthrough for Artificial Intelligence applications regarding board- and video-games. In 2016, AlphaGo, an MCTS-based software agent, outperformed the human world champion of the board game Go. This game was for long considered almost infeasible for machines, due to its immense search space and the need for a long-term strategy. Since this historical success, MCTS is considered as an effective new approach for many other scientific and technical problems. Interestingly, civil structural engineering, as a discipline, offers many tasks whose solution may benefit from intelligent search and in particular from adopting MCTS as a search tool. In this work, we show how MCTS can be adapted to search for suitable solutions of a structural engineering design problem. The problem consists of choosing the load-bearing elements in a reference reinforced concrete structure, so to achieve a set of specific dynamic characteristics. In the paper, we report the results obtained by applying both a plain and a hybrid version of single-agent MCTS. The hybrid approach consists of an integration of both MCTS and classic Genetic Algorithm (GA), the latter also serving as a term of comparison for the results. The study's outcomes may open new perspectives for the adoption of MCTS as a design tool for civil engineers.},
  language  = {en}
}