CHAIR

TECHNICAL

DYNAMICS

The Beyond EDP project aims to strengthen the entrepreneurial discovery process in Europe, boosting the Regional Innovation smart specialisation strategy (RIS3, in short) adopted by Europe in 2014. Knowledge institutes and businesses need each other for innovation and to turn that innovation into saleable products and practical applications. SMEs can fulfil an important role here. Among SMEs are leaders, developers, early adopters, and followers. Most companies can be classed as followers, meaning that innovation is far from a priority for many entrepreneurs.

How can we stimulate European businesses, knowledge institutes, and relevant partners to join forces to discover new ideas which could lead to innovation? That is the central question in Beyond EDP, a European Interreg project formed by eleven partners from nine countries.

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The ongoing demand to reduce CO2 emissions and fuel consumption of engines while increasing performance is increasingly leading to downsizing in combination with high-load concepts. Turbochargers can be used to increase the effective mean pressure. In the turbocharger, the exhaust gas energy of the engine is converted into rotational energy by a turbine, which in turn is used to increase the boost pressure of the engine via a compressor. This can significantly increase the efficiency of the overall engine process. From a thermodynamic point of view, the highest possible turbocharger shaft speeds should be aimed for, whereas from a mechanical point of view, these prove to be critical when using plain bearings due to the instabilities that occur. These instabilities are well known as whirl and whip phenomena in rotors mounted in simple radial plain bearings. From a speed nC1, self-excited subharmonic vibrations occur at approximately 0.42 … 0.45 times the rotational frequency with a stable limit cycle (whirl). If this excites a natural frequency of the rotor when the speed is further increased to nC2, this is referred to as whip. The whip frequency remains constant even if the speed is increased further, whereas the bearing becomes unstable and the amplitudes are only limited by the bearing clearance. In order to ensure safe operation beyond nC2, floating bush bearings are used in turbochargers. These are characterized by the fact that the instability occurring on the inner lubricating film is damped by the outer lubricating film and vice versa. This allows the permissible speed range to be increased.
Various efforts have already been made to investigate and expand our understanding of the occurrence of instability (see e.g. FVV - Project Run-up Simulation I ). However, due to the complexity of the topic, further investigation with increased model depth is absolutely necessary to estimate the sensitivities of the influencing parameters. In order to be able to cover the widest possible range of influencing parameters, a numerical solution of the descriptive thermohydroelastic differential equations should be used as a starting point. This means that there are no restrictions, such as those imposed by the use of the impedance method in the FVV - Project Ramp-up Simulation I. Taking into account practicable calculation times for a ramp-up and the results of a systematic DoE study, suitable simplifications must be made within the framework of a permissible mapping quality. The aim of the research project is therefore to reliably map the subharmonic oscillations and instabilities occurring during turbocharger run-up in frequency and amplitude values.
This text was translated with DeepL

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Im Rahmen des Projektes erfolgt eine Kopplung der Elastohydrodynamik an Mehrkörpersimulationsprogramme (MKS). Ziel ist die möglichst vollständige Beschreibung von Gleit- und Wälzlagerung unter Berücksichtgung der real auftretenden Kräft z.B. in Kurbeltrieben. Es handelt sich hierbei um ein Verbundprojekt im Rahmen des LSA Schwerpunktes Automotive.

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NiSIS is a European Project under the Co-ordinated Action (CA) scheme with the following overall mission aims. Encourage cross-disciplinary team-based thinking to cross-fertilise engineering and life science understanding into advanced inter-operable systems. Progress the theme of adaptivity beyond curiosity and basic earlier engineering concepts and theory, via the spur of naturally-occurring phenomena and self-emergent systems. Elaborate the themes of hierarchy, modularity, redundancy, learning capacity etc in pursuit of greater robustness and reliability against uncertainties, time-variations and fault conditions for large information systems. Incorporate the large body of knowledge on systems dynamics, modelling and identification/estimation into hybrid structures based on intelligent paradigms. Develop a Taxonomy and Strategic Roadmap to describe the state-of-the-art knowledge in the different disciplines about intelligent systems and to signpost a future for integration of deeper nature-inspired concepts into smart devices and systems. Provide training and education across the relevant disciplines via workshops, symposia, Best Practice Guidelines etc. and foster Technology Transfer via competitive team-based feasibility Workshops on realistic benchmarking problems.

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Entwicklung eines Lagerungskonzeptes für schnelldrehende elastisch gelagerte Rotorsysteme. Hiebei werden speziell die Materialeigenschaften der Elastomerkomponenten auf die Rotordynamik untersucht. Ziel ist die Entwicklung einer Lagerung, die bezgl. Unwuchttoleranz und Stabilität einen sicheren Betrieb bei hohen Drehzahlen ermöglicht und die Beschreibung von Rotor-Welle-Kopplungen. Im Rahmen des Projektes wird das FEM- Programm FERAN entwickelt.

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Ziel des Projekts ist die Neuentwicklung eines Zentrifugenrotors, der die Teilfunktionen Separation und Trennung unterschiedlicher Komponenten eines Mehrphasenfluids ermöglicht. Dieser Rotor stellt durch die unterschiedlichen Befüllungszustände während des Betriebes hohe Anforderungen an die Konzeption des Antriebes und die zugehörige Rotordynamik.

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Ziel des Projkets ist die Untersuchung des Einflusses der Fundamentmodellierung auf die Rotordynamik einer Kraftwerksturbine. Hierzu sollen neue Kopllungsmethoden entwickelt werden, die eine Integration von FE-Modellierungen eines Fundamentes an spezielle Mehrkörperprogramme zur Rotordynamik ermöglicht.

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Ziel des Projektes ist die schwingungsoptimierte Auslegung eines dentalen Ultraschallscalers zur Entfernung subgingivaler Konkremnete auf humanen Zahnoberflächen. Die Abtragsleistung wird maßgeblich durch die erziebaren Schwingungsamplituden an der Instrumentenspitze erreicht. Mittels FEM- Rechnungen und der Nutzung von Optimierungsstrategien sollen Scaleraufbau und Form der Nadeln verbessert werden.

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Ziel des Projektes ist die Entwicklung eines Rotorüberwachungssystems für Drehzahlen oberhalb von 30000 U/min. Hierzu sind neue Methoden der Signalverarbeitung notwendig. Klasssiche Verfahren zur Wälzlagerüberwachung versagen, weil die hohen Drehzhalen zu einer permanenten Strukturanregung führen. Es werden neue Methoden auf der Basis der ICA entwickelt.

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