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Rapid dynamic load estimation procedure for lifting propellers in forward flight
No full textLifting propellers operate at oblique inflow and thus encounter severe dynamic loads during forward flight, impacting structural integrity, fatigue, and vibration. Numerical optimisation approaches consider aerodynamic, structural mechanical, and aeroacoustic aspects within preliminary design. To also account for dynamic loads during forward flight, a novel procedure allows their rapid estimation. Based on steady-state simulations combining strip theory and beam finite elements, aerodynamic excitation, damping, and stiffness are defined in the frequency domain. Loads are derived through a linear inflow model and quasi-steady aerodynamics. Damping and stiffness loads are linearised and transferred into matrix form to calculate the frequency response. The computationally expensive need for simulations in the time domain is thus avoided. Applicability extends to both fixed and variable pitch lifting propellers utilised in large multicopters for cargo or passenger transportation. Comparisons to time-marching simulations show good agreement with deviations of approximately 10%. The analytical derivation yields physical insights to understand and reduce dynamic loads and their magnification due to resonance
Zugangsordnung für die Masterstudiengänge „Information Systems“ und „Information Systems (Part-time)“, Studienbeginn ab Wintersemester 2024/25
No full textPrüfungsordnung für die Bachelorstudiengänge „Mechatronik“, „Mechatronik (Teilzeit)“ und „Dualer Studiengang Mechatronik (DIMech)“, Studienbeginn ab Wintersemester 2024/25
No full textOrdnung zur Änderung der Prüfungsordnung für den Bachelorstudiengang „Electrical Engineering (AOS)“, Studienbeginn ab Wintersemester 2024/25
No full textInvestigation of particle size distribution and ultrafiltration of digestates from short-fibre residues in paper mills
No full textIndustrial digestates from short-fibre residues, generated in paper recycling mills, are driving interest in resource recovery. This study aims to explore their potential for water recovery. Understanding particle dynamics aids in optimizing dewatering for digestate management. The particle size distribution in this study revealed significant fractions: 20 μm (11–16%). Pre-treatment with Na4P2O7 and H2O2 enhances settling and lowers total dissolved solids (TDSs) but results in variation of size distribution. Additionally, this study investigates further water reuse in paper mills, focusing on the quality of ultrafiltration (UF) permeate obtained from the digestate of short fibres. UF permeate analysis reveals deviations from freshwater standards in paper mills. Despite effective TS removal, UF permeate falls short of paper mill water standards due to high TDSs, electrical conductivity, and nutrient concentrations, necessitating further downstream treatment with nanofiltration or reverse osmosis. A substantial reduction of permeate flux from 31 to 5 L/(m2·h) over the time indicated fouling and inefficient membrane wash. The silt density index of the UF membrane at 30 min registered 2.1, suggesting potential fouling. Further investigations on optimizing UF operations to enhance permeate flux and exploring alternative UF membranes are required
A novel optical approach for assessing in vivo bone segment deformation and its application in muscle-bone relationship studies in humans
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Transformatives Forschen, Lehren und Handeln im Rheinischen Braunkohlerevier
No full textDie Institution Hochschule hat das Potenzial, über transformatives Forschen und Lehren und den entsprechenden Wissenstransfer in den lokalen Kontext strategisch-verlässliche Partnerin der Großen Transformation zur Nachhaltigkeit zu werden und bei der Ausbildung von Pionierinnen und Pionieren des Wandels mitzuwirken. Der Lehr- und Forschungsschwerpunkt „Zukunftsfähige Transformation” am Fachbereich Architektur der FH Aachen widmet sich seit 2020 dem Tagebauumfeld Hambach im Rheinischen Revier, um dort angewandt und in Kooperation neue Narrative, innovative Prozesse, ortsbezogene Konzepte und strategische Projekte zu entwickeln und umzusetzen
Advanced two phase flow model for transient molten salt receiver system simulation
No full textIn 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
Analysis of an integrated CSP-PV hybrid power plant
No full textIn the past, CSP and PV have been seen as competing technologies. Despite massive reductions in the electricity generation costs of CSP plants, PV power generation is - at least during sunshine hours - significantly cheaper. If electricity is required not only during the daytime, but around the clock, CSP with its inherent thermal energy storage gets an advantage in terms of LEC. There are a few examples of projects in which CSP plants and PV plants have been co-located, meaning that they feed into the same grid connection point and ideally optimize their operation strategy to yield an overall benefit. In the past eight years, TSK Flagsol has developed a plant concept, which merges both solar technologies into one highly Integrated CSP-PV-Hybrid (ICPH) power plant. Here, unlike in simply co-located concepts, as analyzed e.g. in [1] – [4], excess PV power that would have to be dumped is used in electric molten salt heaters to increase the storage temperature, improving storage and conversion efficiency. The authors demonstrate the electricity cost sensitivity to subsystem sizing for various market scenarios, and compare the resulting optimized ICPH plants with co-located hybrid plants. Independent of the three feed-in tariffs that have been assumed, the ICPH plant shows an electricity cost advantage of almost 20% while maintaining a high degree of flexibility in power dispatch as it is characteristic for CSP power plants. As all components of such an innovative concept are well proven, the system is ready for commercial market implementation. A first project is already contracted and in early engineering execution