TY - JOUR A1 - Schwager, Christian A1 - Flesch, Robert A1 - Schwarzbözl, Peter A1 - Herrmann, Ulf A1 - Teixeira Boura, Cristiano José T1 - Advanced two phase flow model for transient molten salt receiver system simulation JF - Solar Energy N2 - 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. KW - Molten salt solar tower KW - Molten salt receiver system KW - Dynamic simulation KW - Two-phase modelling KW - Transient flux distribution Y1 - 2022 U6 - http://dx.doi.org/10.1016/j.solener.2021.12.065 SN - 0038-092X (print) SN - 1471-1257 (online) VL - 232 SP - 362 EP - 375 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Schüller-Ruhl, Aaron A1 - Dinstühler, Leonard A1 - Senger, Thorsten A1 - Bergfeld, Stefan A1 - Ingenhag, Christian A1 - Fleischhaker, Robert ED - Mackenzie, Jacob T1 - Direct fabrication of arbitrary phase masks in optical glass via ultra-short pulsed laser writing of refractive index modifications JF - Applied Physics B N2 - We study the possibility to fabricate an arbitrary phase mask in a one-step laser-writing process inside the volume of an optical glass substrate. We derive the phase mask from a Gerchberg–Saxton-type algorithm as an array and create each individual phase shift using a refractive index modification of variable axial length. We realize the variable axial length by superimposing refractive index modifications induced by an ultra-short pulsed laser at different focusing depth. Each single modification is created by applying 1000 pulses with 15 μJ pulse energy at 100 kHz to a fixed spot of 25 μm diameter and the focus is then shifted axially in steps of 10 μm. With several proof-of-principle examples, we show the feasibility of our method. In particular, we identify the induced refractive index change to about a value of Δn=1.5⋅10−3. We also determine our current limitations by calculating the overlap in the form of a scalar product and we discuss possible future improvements. Y1 - 2022 U6 - http://dx.doi.org/10.1007/s00340-022-07928-2 SN - 1432-0649 (Online) SN - 0946-2171 (Print) N1 - Corresponding author: Robert Fleischhaker VL - 128 IS - Article number: 208 SP - 1 EP - 11 PB - Springer CY - Berlin ER - TY - GEN A1 - Steuer-Dankert, Linda A1 - Bernhard, Sebastian A1 - Langolf, Jessica A1 - Leicht-Scholten, Carmen T1 - Managing change and acceptance of digitalization strategies - Implementing the vision of „Internet of Production“ (IoP) in existing corporate structures T2 - Textile Impulse für die Zukunft: Aachen-Dresden-Denkendorf International Textile Conference 2022 : 1. – 2. Dezember 2022, Eurogress Aachen N2 - The vision of the Internet of Production is to enable a new level of crossdomain collaboration by providing semantically adequate and context-aware data from production, development & usage in real-time. Y1 - 2022 SP - 153 EP - 153 ER - TY - CHAP A1 - Steuer-Dankert, Linda A1 - Leicht-Scholten, Carmen T1 - Perceiving diversity : an explorative approach in a complex research organization. T2 - Diversity and discrimination in research organizations N2 - Diversity management is seen as a decisive factor for ensuring the development of socially responsible innovations (Beacham and Shambaugh, 2011; Sonntag, 2014; López, 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. KW - Diversity management KW - Organizational culture KW - Change management KW - Psychological concepts KW - Perception Y1 - 2022 SN - 978-1-80117-959-1 (Print) SN - 978-1-80117-956-0 (Online) U6 - http://dx.doi.org/10.1108/978-1-80117-956-020221010 SP - 365 EP - 392 PB - Emerald Publishing Limited CY - Bingley ER - TY - CHAP A1 - Striebing, Clemens A1 - Müller, Jörg A1 - Schraudner, Martina A1 - Gewinner, Irina Valerie A1 - Guerrero Morales, Patricia A1 - Hochfeld, Katharina A1 - Hoffman, Shekinah A1 - Kmec, Julie A. A1 - Nguyen, Huu Minh A1 - Schneider, Jannick A1 - Sheridan, Jennifer A1 - Steuer-Dankert, Linda A1 - Trimble O'Connor, Lindsey A1 - Vandevelde-Rougale, Agnès T1 - Promoting diversity and combatting discrimination in research organizations: a practitioner’s guide T2 - Diversity and discrimination in research organizations N2 - 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.” KW - Inclusive work climate KW - lessons learned KW - policy recommendations KW - recommendations for actions KW - bullying Y1 - 2022 SN - 978-1-80117-959-1 (Print) SN - 978-1-80117-956-0 (Online) U6 - http://dx.doi.org/10.1108/978-1-80117-956-020221012 SP - 421 EP - 442 PB - Emerald Publishing Limited CY - Bingley ER - TY - CHAP A1 - Weber, Felix A1 - Bomholt, Frederik A1 - Butenweg, Christoph ED - Bergmeister, Konrad ED - Fingerloos, Frank ED - Wörner, Johann-Dietrich T1 - Erdbeben- und Schwingungsschutz von Bauwerken T2 - 2023 BetonKalender: Wasserundurchlässiger Beton, Brückenbau N2 - Dieser Beitrag beschreibt die herkömmlichen Maßnahmen wie die Kapazitätsbemessung der Tragwerksstruktur, die Isolation des Bauwerks mittels Basisisolatoren, die Dämpfungserhöhung der Struktur mittels Inter-Story-Dämpfern und die Schwingungsreduktion mittels Schwingungstilgern gegen Einwirkungen durch Erdbeben, Wind, Verkehr und Personen auf die Bauwerke. Ergänzend wird die erdbebengerechte Auslegung und Isolation von nichttragenden Bauteilen behandelt. Für die betrachteten Systeme werden die Bewegungsdifferenzialgleichungen unter Berücksichtigung der wesentlichen Nichtlinearitäten angegeben. Die vorgestellten Weiterentwicklungen in den Bereichen der Basisisolatoren, Dämpfern und Schwingungstilgern zeigen, dass das modellbasierte Design mittels Simulation ein sehr effektives, ökonomisches und dank der heutigen Computerleistung auch zeiteffizientes Werkzeug darstellt. Y1 - 2022 SN - 9783433611180 SN - 9783433033753 U6 - http://dx.doi.org/10.1002/9783433611180.ch16 N1 - Beton-Kalender, 112. Jahrgang (2023): Wasserundurchlässiger Beton, Brückenbau ausleihbar unter der Sig. 11 XCF 3-2023,2 SP - 779 EP - 859 PB - Ernst & Sohn CY - Berlin ER - TY - CHAP A1 - Zahra, Mahdi A1 - Phani Srujan, Merige A1 - Caminos, Ricardo Alexander Chico A1 - Schmitz, Pascal A1 - Herrmann, Ulf A1 - Teixeira Boura, Cristiano José A1 - Schmitz, Mark A1 - Gielen, Hans A1 - Gedle, Yibekal A1 - Dersch, Jürgen T1 - Modeling the thermal behavior of solar salt in electrical resistance heaters for the application in PV-CSP hybrid power plants T2 - SOLARPACES 2020 N2 - 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. KW - Solar thermal technologies KW - Hybrid energy system KW - Concentrated solar power KW - Energy storage KW - Photovoltaics Y1 - 2022 SN - 978-0-7354-4195-8 U6 - http://dx.doi.org/10.1063/5.0086268 SN - 1551-7616 (online) SN - 0094-243X (print) N1 - 26th International Conference on Concentrating Solar Power and Chemical Energy Systems 28 September–2 October 2020 Freiburg, Germany IS - 2445 / 1 PB - AIP conference proceedings / American Institute of Physics CY - Melville, NY ER -