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Unsteady LPT Blade Effects on Outlet Guide Vane Heat Transfer. Analysis of transient thermal loads induced by blade wakes in turbine rear structures
No full textAccurate thermal modeling in turbine rear structures (TRS) of aero-engines is crucial due to the high temperature air flow and cyclic thermal stresses induced by unsteady blade wakes from upstream low-pressure turbine (LPT) blades. Current industry practices predominantly rely on steady-state computational fluid dynamics (CFD) simulations to predict heat transfer coefficients (HTC). However, these models commonly underpredict HTC when compared to experimental measurements, primarily due to their inability to capture transient and unsteady effects.
In collaboration with GKN Aerospace Sweden, this thesis has focused on developing and analysing a two-dimensional transient CFD model of Outlet Guide Vane (OGV) heat transfer using sliding mesh techniques and advanced turbulence models, notably the SSTtransition turbulence model. Validation of this model was conducted against experimental HTC data obtained from a 1.5-stage test rig at Chalmers. The transient simulations reveal clear periodic fluctuations in HTC due to the rotor blade wakes, phenomena inherently missed by steady-state models.
However, despite capturing temporal HTC variations and unsteady flow behaviour the transient CFD approach still resulted in HTC underpredictions compared to experimental data as well as 2D and 3D steady-state CFD models. This discrepancy is attributed not only to limitations inherent in two-dimensional modeling but also to the need for more advanced turbulence modeling and potential inaccuracies stemming from an outdated mesh study based on incorrect boundary conditions. The study suggests further research should focus on resolving these issues through refined turbulence modeling strategies, accurate boundary condition implementation, and rigorous mesh studies to enhance predictive accuracy as well as industrial relevance and applicability
Utvärdering av korroderade betongpålar i hamnkonstruktioner
No full textDenna rapport behandlar utvärdering av armeringskorrosion i armerade betongpålar i marin miljö, med syfte att analysera skadornas omfattning och fördelning efter långtidsexponering i aggressiv omgivning. Två armeringsjärn extraherades från en 50 till 60 år gammal påle i Göteborgs Hamn. Genom segmentering, sandblästring och 3D-skanning togs högupplösta punktmoln fram, vilka analyserades i MATLAB för att kvantifiera förlust i tvärsnittsarea och volym.
Studien visar att metoden med 3D-skanning kombinerat med numerisk analys är ett kraftfullt verktyg för att identifiera riskzoner och bedöma tillståndet i armerad betong. Resultaten tyder på att flera korrosionsmekanismer, bland annat kloridinducerad och anaerob korrosion, samverkat. Trots vissa metodologiska osäkerheter har arbetet potential att komplettera traditionella hamninspektioner, särskilt i kombination med fiberoptiska mätningar. Metoden lämpar sig väl som underlag för framtida tillståndsbedömningar, men vidare studier med fler prov och referensdata rekommenderas för ökad tillförlitlighet
An NLP-based System for Automated Compliance Analysis and Requirement Classification in Engineering Applications
No full textRegulatory compliance is a critical challenge in engineering product development, particularly in industries governed by complex and frequently evolving standards. This research, conducted in collaboration with Volvo Penta, explores the use of Natural Language Processing (NLP) techniques to automate the classification and interpretation of regulatory clauses in support of early-stage requirements analysis, with a focus on ensuring traceability, usability, and transparency in the decision making process. The proposed method integrates rule-based preprocessing, domain specific keyword enrichment, semantic similarity retrieval using dense embeddings, and reasoning about individual regulatory statements using large language models (LLMs). The system is connected to Volvo Penta’s SystemWeaver platform to sup port traceable, explainable, and human-reviewable predictions at the clause level. By automating the identification and interpretation of relevant regulatory content, the system reduces manual workload, improves consistency, and enables scalable compliance workflows. Evaluation through both quantitative analysis and expert feedback indicates strong alignment with human judgment and demonstrates the system’s value as a decision-support tool in industrial engineering compliance processes. While limitations remain in handling edge cases and ambiguous regulatory language, results suggest that NLP-driven methods can meaningfully support scalable, traceable, and more efficient compliance processes in industrial engineering settings
Digital Twins on Multi-Purpose Robotic Cell with Visual Components Simulation Software
No full textThis thesis demonstrates how a Digital Twin (DT) can be realized using Visual Components, either through direct connection to a robot controller or via Industrial Internet of Things (IIoT) software, to enable a more beneficial solution. A methodology on how to approach a DT implementation is proposed, integrating both the virtual and physical commissioning. Details include how to design a robot cell and a process in Visual Components, and how to pair data from sensors in the physical world to the simulation. The study also identifies key challenges of DT implementation in commercial contexts, such as cybersecurity and IIoT platform integration.
Finally, the use of IIoT platforms Ignition and HighByte is explored, highlighting their respective challenges in DT development
Data Hide and Seek is Over!
No full textA complete pipeline is presented for automatic annotation and retrieval of multimodal vehicle data, using synchronized front-facing camera images and LiDAR point clouds. Driving scenes are classified across four categories: road condition, road type, lighting, and visibility. A dataset of 1,878 one-minute segments is constructed from over 200 hours of real-world driving. Segments are manually labeled to provide ground-truth annotations for training and evaluation, and selected to ensure an even distribution across all scenario categories.
Separate models are trained for each sensor: a VGG19-based CNN for image classification and a lightweight PointNet for LiDAR point clouds. The best-performing vision model achieves strong results across all categories, while the LiDAR model performs best on road condition and visibility. A fusion model, implemented as a small multilayer perceptron, combines outputs from both sensors and outperforms the individual models, particularly on more difficult scenarios and categories.
Sequence-level aggregation of predictions is applied to reduce frame-level variation and improve accuracy. A proof-of-concept data retrieval interface is also presented, enabling users to filter and inspect data based on predicted labels and confidence scores, and to explore both camera images and LiDAR point clouds for each retrieved segment
Enhancing the user experience for an energy metering platform - The full process from problem identification to concept development
No full textAs energy consumption continues to rise, the need for effective tools that promote energy awareness and encourage sustainable behaviour has become increasingly important. This study explores how the user experience (UX) of energy metering data presentation in a digital platform can be enhanced and thereby support behavioural change toward energy efficiency. The project was conducted in collaboration with Elvaco, a company specializing in smart energy metering solutions, and focused on improving the user experience of their new digital platform, Play. The initial phase of this study involved problem identification through user research, market analysis and literature review to understand the key challenges of Elvaco’s digitalization. One aspect of the findings indicated that end users often are unexperienced regarding energy systems and lack knowledge of supporting insights and actionable recommendations, leading to limited behavioural change. By applying user-centred design principles, the study examined how end users interact with energy data and what design elements facilitate better understanding and decision-making. A combination of usability testing, interviews and prototyping in Figma was used to develop and evaluate approaches in presenting energy data in a clear and actionable way. Particular attention was given to behaviour-oriented design, including knowledge enhancement and decision-support tools, to motivate users toward more sustainable energy consumption. The results indicate that a well-structured, intuitive data presentation, combined with additional support and recommendations, significantly improves user engagement and the ability to take informed actions. This study contributes to the field of sustainable UX design by demonstrating how digital solutions can bridge the gap between energy awareness and behavioural change
Trådlös laddning av luftburna drönare - Wireless charging of airborne drones
No full textSammanfattning
Användningen av drönare och deras tillämpningsområden har ökat kraftigt under de senaste åren. Ett växande användningsområde är autonomisering av arbetsuppgifter, såsom rekognoscering av kraftledningar. För att möjliggöra full autonomi krävs även en autonom laddningsmetod. I detta projekt undersöks möjligheten att konstruera trådlös laddare med hjälp av induktiv kraftöverföring för att sedan utvärdera dess prestanda. Rapporten inleds med en genomgång av den teoretiska bakgrund som är central för projektet. Därefter beskrivs projektets olika faser i kronologisk ordning från simuleringar med finita elementmetoden och kretssimuleringar till konstruktionen av en fysisk prototyp. Olika spoltopologiers egenskaper vid felplaceringar utvärderas, där en större primärspole gentemot sekundärspole ger mest fördelaktigt resultat vid felplacering. Projektet resulterar även i en prototyp som överför effekt med en uppmätt maximal verkningsgrad på 69,78 %. En god överensstämmelse mellan simuleringar och experiment validerar resultaten. Effektförluster kopplas främst till spolarnas resistans, avvikelser i resonansfrekvensen, lågt Q-värde och oönskade transienta förlopp.
Abstract
The use of drones and their application areas has seen a significant increase in recent years. One emerging application is the automation of tasks such as power line inspection. To enable full autonomy, an autonomous charging method is also required. This project investigates the possibility of constructing a wireless charger using inductive power transfer and then evaluating it’s performance. The report begins with an overview of the fundamental theoretical background that is necessary the project. Next, the project’s phases are presented in chronological order, covering the development process from finite element method simulations and Simulink to the construction of a physical prototype The behavior of different coil topologies under misalignment is evaluated, where a larger primary coil relative to the secondary coil yields the most favorable results. The project culminates in a prototype capable of transferring power with a measured maximum efficiency of 69.78%. Strong agreement between simulation and experimental results validates the outcomes. Power losses are primarily attributed to coil resistance, deviations in resonant frequency, low Q- factor, and undesired transient phenomena
Optimizing Stream Engines for use in eFPGAs on Radiation Hardened SoCs
No full textSystems on a Chip (SoCs) are becoming increasingly common for use in most computational domains as heterogeneous hardware architectures prove themselves
very efficient and powerful. The space domain is one such example and poses a
plethora of challenging design constraints, which become even more pronounced
in the context of radiation hardened embedded Field Programmable Gate Arrays
(eFPGAs). eFPGAs lend themselves to supporting powerful hardware accelerators
(HAs), where data is streamed in by the use of a stream engine. Due to the relatively
small amount of programmable logic in eFPGAs, the stream engine supporting the
HA must be made as resource efficient as possible. Though, to the best of the
authors knowledge, there is no previous work exploring resource optimized stream
engines for use on eFPGA.
In this thesis, we implement a performance and resource efficient stream engine
for eFPGAs. The proposed stream engine – named GANIMEDE – achieved a
communication link utilization of 94.5% accounted for protocol overheads while only
occupying 2.1% of the total available resources provided by the targeted eFPGA. In
addition, this thesis offers a discussion on desirable properties in stream engines
and presents parts of supported protocols that should be implemented on the SoC
instead of the eFPGA
Ger svanenmärkning ett affärsmässigt mervärde för bostadsutvecklare; en kvalitativ studie av märkningens effekt på bostadsköpares betalningsvilja bankernas finansieringsvillkor och utvecklares affärsstrategier
No full textBygg- och fastighetssektorn står för en betydande del av Sveriges växthusgasutsläpp, vilket
har lett till ett ökat fokus på hållbarhetsåtgärder inom branschen. En av dessa åtgärder är
användningen av miljöcertifieringar, där Svanenmärkningen är en av de mest etablerade i
Norden. Det är ännu oklart vilken grad certifieringen bidrar till konkreta affärsfördelar för
bostadsutvecklare. Denna studie syftar till att undersöka om och hur Svanenmärkning kan
generera affärsmässiga mervärden inom svensk bostadsutveckling, med fokus på tre centrala
aspekter: köpares betalningsvilja, bankernas finansieringsvillkor samt utvecklares strategiska
beslut.
Studien tillämpar en metodkombination där kvantitativa data har samlats in genom en enkät
riktad till bostadsköpare, och kvalitativa data genom semistrukturerade intervjuer med
representanter från banker och bostadsutvecklingsföretag. Den sekventiella designen
möjliggör en fördjupad förståelse för hur olika aktörer uppfattar märkningens roll och värde.
Resultatet visar att Svanenmärkning generellt uppfattas som en positiv signal för kvalitet och
hållbarhet, särskilt bland utvecklare och banker. Enkätsvaren antyder att vissa bostadsköpare
kan vara villiga att betala mer för en Svanenmärkt bostad, men detta stöds inte av
marknadsdata eller av annan forskning. I intervjuer med banker framkom att märkningen
sällan påverkar vare sig värdering eller kreditvillkor större grad, även om den i vissa fall kan
stärka projektets trovärdighet och förbättra chanserna till grön finansiering. För utvecklare
fungerar certifieringen främst som ett verktyg för strategisk positionering, snarare än som en
garanti för högre lönsamhet.
Sammanfattningsvis visar studien att Svanenmärkning har potential att generera affärsmässiga
mervärden, men att dessa effekter i hög grad är beroende av aktörens position på marknaden
samt det omgivande institutionella ramverket. För att märkningen ska få ett starkare
genomslag i affärsbeslut krävs tydliga ekonomiska incitament, en närmare koppling till
finansiella fördelar och en ökad medvetenhet hos konsumenter om märkningens betydels
What Lies Beneath: Preservation, reconstruction & reuse at Uppåkra archaeological site
No full textNext to a barn on the Scanian countryside, beneath the wheat-fields around the village of Uppåkra, lies the remains of an ancient Scandinavian power-centre. In the 2000s an impressive temple was unearthed, currently a large hall is being excavated. The rest of the settlement lies untouched, still buried in the soil.
Since the inception of the conservation-field in the mid-1800s, the discipline has battled with a central question: Should we restore objects to its former glory, or preserve heritage in its present state, to display the passage of time? The answer either lands at: restoration, preservation, or somewhere in between.
The thesis explores this spectrum of views on conservation, using the design of an archaeological centre at Uppåkra as a testbed for three approaches: Restoration through the reconstruction of a temple, preservation through protection of excavated remains, and the mix of these through the transformation of an old barn into a museum for found artefacts.
The design departs from collecting, mapping, and representing the local archaeology. Together with research on similar typologies and conservation approaches.
Keywords: Archaeology, Preservation, Conservation, Restoration, Adaptive Reuse,
The thesis hinges around the span between abstraction and realism in reconstruction practices, exemplified by the abstraction of Venturi, Scott Brown’s “Ghost House” reconstruction of Franklin Court in Philadelphia, USA (1976), and the realism of Jan Gezelius’ reconstruction of Eketorps Fornborg on Öland (1984). While Venturi & Scott Brown’s project renders the massing as an “abstract” framework to reflect a lack of source material, Gezelius does the opposite, creating a “realistic” interpretation, filling knowledge-gaps with educated guesses.
The thesis illustrates how the history of Uppåkra can be communicated beyond the tools of a conventional museum. By erecting an excavation-shelter that showcases the archaeological process, engaging visitors in conservation work in a transformed barn and enabling them to imagine past structures through an abstract reconstruction.
Unlike previous proposals for the site, the design leaves the area largely undisturbed, enabling future excavations. By reusing existing structures and carefully placing new ones on top of past excavations. It suggests a new direction for the tradition of archaeological centres in Sweden