40 research outputs found

    The Need for Dynamic Process Simulation: A Review of Offshore Power‐to‐X Systems

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    The integration of offshore wind energy into Power-to-X (PtX) process chains offers opportunities for the efficient use of renewable energy. This article analyzes different PtX process chain configurations and their adaptation to the offshore environment. However, direct coupling of PtX platforms with fluctuating electrical energy poses major challenges. Dynamic process simulation is presented for analysis of different plant configurations and operating strategies. The article emphasizes the need for interdisciplinary research to consider technological as well as economic and environmental aspects

    Design Strategies for the Process of Additive Manufacturing

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    Additive manufacturing (AM) is a cyclic manufacturing process to create three-dimensional objects layer-by-layer directly from a 3D CAD model. Today AM processes like SLM and SLS are already suitable for direct part production. The processes have little restrictions regarding the shape of the object. The challenge to a designer is to use the unique characteristics of additive manufacturing in the development process to create an added value for the manufacturer and the user of a product. This paper presents two design strategies to use additive manufacturing\u27s benefits in product development. A manufacturing driven design strategy allows a substitution of manufacturing processes at a later stage of the product life cycle, while a function driven design strategy increases the performance of a product. The choice of strategy has great impact on the development process and the design of components. Two cases are presented to explain and illustrate these design strategies

    Design Guidelines for Additive Manufactured Snap-Fit Joints

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    Snap-fit joints are one of the cheapest and fastest connectors available. However, due to geometrical complexity of the joints and the limitations of injection molding, they are used almost exclusively in large-scale manufactured products. Additive manufacturing offers the possibility to create end-user products in small and medium numbers with almost unlimited design complexity. This clears the way for new solutions using snap-fit joints to be explored. In this contribution, the existing design guidelines for snap-fit joints are challenged with the design potentials of additive manufacturing. The general working principles of snap-fit joints prove to be simple, clear, and safe independent of the manufacturing process. While the principles remain unchanged, the advantages of additive manufacturing are utilized to improve the integration in the product and the user handling. By applying the design restrictions of the additive manufacturing processes Fused Deposition Modeling (FDM) and Selective Laser Sintering (SLS) the existing guidelines are extended for new manufacturing processes. To demonstrate the new concepts and the capabilities of additive manufactured snap-fit joints a showcase is conceptualized, designed in detail and produced using Fused Deposition Modeling and Selective Laser Sintering. A lid of a container, similar to a jar, is designed as an integrated single component. Aspects of haptics and usability are integrated, resulting in a lid that can easily be assembled and disassembled using one hand only. The design features springs and snap-fit joints adapted to the advantages and limitations of additive manufacturing

    Downsizing Sustainable Aviation Fuel Production with Additive Manufacturing-An Experimental Study on a 3D printed Reactor for Fischer-Tropsch Synthesis

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    Sustainable aviation fuels (SAF) are needed in large quantities to reduce the negative impact of flying on the climate. So-called power-to-liquid (PtL) plants can produce SAF from renewable electricity, water, and carbon dioxide. Reactors for these processes that are suitable for flexible operation are difficult to manufacture. Metal 3D printing, also known as additive manufacturing (AM), enables the fabrication of process equipment, such as chemical reactors, with highly optimized functions. In this publication, we present an AM reactor design and conduct experiments for Fischer-Tropsch synthesis (FTS) under challenging conditions. The design includes heating, cooling, and sensing, among others, and can be easily fabricated without welding. We confirm that our reactor has excellent temperature control and high productivity of FTS products up to 800 kgC5+ mcat−3 h−1 (mass flow rate of hydrocarbons, liquid or solid at ambient conditions, per catalyst volume). The typical space-time yield for conventional multi-tubular Fischer-Tropsch reactors is ~100 kgC5+ mcat−3 h−1. The increased productivity is achieved by designing reactor structures in which the channels for catalyst and cooling/heating fluid are in the millimeter range. With the effective control of heat release, we observe neither the formation of hot spots nor catalyst deactivation

    Considering Part Orientation in Design for Additive Manufacturing

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    Additive Manufacturing (AM) is established not only in prototyping, but also in serial production of end-use products. To use the full potential of the production technology the restrictions of current additive manufacturing processes (like support structures in Selective Laser Melting) must be considered in the design process. Especially the compliance with design rules from early design stages on is important in AM serial production, due to production quantities and the resulting scale effect. The part orientation in the build space has a strong influence on many quality characteristics. In order to use the full potential and to consider the restrictions from the start, a design guideline is necessary to support the whole design process. For this purpose, this paper presents a framework for design guidelines. The framework distinguishes between process characteristics, design principles and design rules; each supporting the designer during different stages of the design process. Furthermore, the paper examines the influence of part orientation in existing design rules and elaborates its importance. Based on this result, the design principle “early determination of part orientation” is presented, which includes a process for determining the part orientation in early stage of the design process. In addition, a design process for additive manufactured parts is demonstrated on an extensive showcase, following the guideline framework and including the principle for early determination of part orientation. The presented framework proved to be helpful in the design process and will be used in the future to collect more process characteristics, design principles and rules

    Design Automation and Additive Manufacturing for Anatomically Diversified Medical Simulators

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    The education and continuous exercise of manual skills in invasive medical procedures requires training environments that are safe, cost efficient and realistic. While body parts of humans and animals offer the most realism they are expensive and challenging in storage, handling and disposal. Therefore, training scenarios for medical staff commonly use artificial simulators to practice individual skills and team performance. These simulators usually do not reflect the diversity in human anatomy. Simulators for a certain task are commonly offered only in one shape and size to reduce cost in design and manufacturing. A more diverse anatomy could improve the training of medical staff. This work uses additive manufacturing for the cost efficient production of molds and components for silicone casted customized simulators. Furthermore a design automated approach is presented that allows non-engineers to specify the desired anatomy. The process chain is validated on a simulator for pneumothorax decompression. The main element of the simulator is an insert, which is cut and stitched during the procedure. The insert is a single-use disposable representing ribs, muscles, fat and skin. The new simulator insert offers improved aesthetic and tactile properties. The automated design and additive manufacturing allow non-engineers to adapt the insert to body mass index, age, gender and ethnicity

    Fabrication of Sectionally Permeable Components with Curved Surface by Laser‐Beam Powder‐Bed Fusion

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    Devices in process engineering often include permeable components. As shown in our recent work for planar components, laser-beam powder bed fusion offers the opportunity to integrate permeable sections into complex monolithic metal parts in one go. This paper extends the approach to components with curved surfaces. Different scan strategies were investigated for their effects on surface morphology and permeability of tubular samples. It was found that in order to ensure consistent properties of a permeable tube, different starting points or rotation of the scan vectors have to be used

    Funktionsintegration im Werkzeugbau durch laseradditive Fertigung

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    Werkzeugbauer stellen anspruchsvolle Spritzgießwerkzeuge als Einzelanfertigung oder in kleiner StĂŒckzahl her. Dabei unterliegen sie einem hohen Zeit- und Kostendruck durch die Forderung der Kunden nach einer kurzen Time-to-Market und der Konkurrenz aus NiedriglohnlĂ€ndern. Eine Innovation des Werkzeugbaus zur Reduzierung von Zeit und Kosten ist die Integration von zusĂ€tzlichen Funktionen in bestehende Komponenten. Am Institut fĂŒr Laser- und Anlagensystemtechnik der TU Hamburg-Harburg wurde in Zusammenarbeit mit Werkzeugbau Siegfried Hofmann und Concept Laser ein Druckluftauswerfersystem fĂŒr Spritzgießwerkzeuge entwickelt. Dieses System kann klassische Auswerferstifte vollstĂ€ndig ersetzen. Die Integration von Druckluftauswerfern in laseradditiv gefertigte WerkzeugeinsĂ€tze mit konturnaher KĂŒhlung erfolgt kostenneutral, da sich die Fertigungszeit des Einsatzes durch das zusĂ€tzliche System nicht verlĂ€ngert und eine Druckluftsteuerung bereits in Spritzgießmaschinen vorhanden ist. ZusĂ€tzlich entfĂ€llt durch das Druckluftauswerfersystem das komplette mechanische Auswerferpaket. Durch diese Einsparungen reduzieren sich Zeit und Kosten fĂŒr das Werkzeug

    Teaching agile hardware development with an open‐source engineering simulator: An evaluation with industry participants

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    Educational games are increasingly used to teach Agile development approaches to practitioners. Most of these training modules simplify the development environment, for example, by using LEGO bricks or playing cards. This oversimplification has been shown to result in limited transferability of learning to industrial practice. Furthermore, there is a lack of teaching modules that specifically address the challenges of applying Agile to physical products. In this paper, we present an open-source educational game that realistically simulates a hardware development project to teach Agile principles. Over 2 days, participants design, manufacture, and test modifications for a physical wire bending machine within an authentic engineering and production setting. The training mimics the typical roles, processes, and tools of industrial engineering teams to reflect the challenges of Agile hardware development. The module was evaluated with 44 industry professionals regarding perceived learning and user reaction. A combination of quantitative and qualitative methods was used for the experimental evaluation. The results showed a positive learning effect as the participants\u27 average agreement with Agile principles increased through the training. Concerning user reaction, respondents reported a high degree of relevance, interaction, and confidence, indicating that the realistic simulation of the hardware development appropriately balanced the degree of realism with simplicity. The study showcases the opportunities of properly aligning game components to provoke learning situations targeted by the instructors. It contributes to the extant literature by providing a design framework (product, process, setting, and instruction) and open-source access to the tools used for implementation
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