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Jacopo Zamboni

Faculty of Aeropace Engineering Jacopo obtained his master’s degree in Aerospace Engineering. For his thesis he developed a method for the conceptual design of hybrid electric aircraft. Society demands future aircraft to be more fuel-efficient to limit their negative impact on our climate and still warrant a sustainable growth of the aviation industry. Jacopo developed a design methodology based on fundamental theories of flight, electrical engineering, and aircraft design. He demonstrated the versatility of his method by designing various future aircraft relying on different hybrid-electric architectures. By performing a thorough validation of each of the subcomponents of the methodology, he convinced the graduation committee of the validity of his results. Furthermore, Jacopo outlined three distinctive paths forward for hybrid-electric propulsion, with overall reductions in energy consumption ranging between 6% and 35% for the most conservative and most progressive technology assumptions, respectively. Jacopo received a 9 for his thesis and will present the contents of his work on the international AIAA SCITECH conference. “Jacopo is an excellent student with a deep passion for aviation and aircraft design in particular. His thesis is original, scientifically sound and very relevant with respect to developments within society” Graduation committee – Dr R. Vos, Prof. L. L. M. Veldhuis, P. C. Roling MSc, R. de Vries MSc Thesis synposis As the aviation sector keeps expanding, a growing interest in technologies that can reduce the dependency from non-renewable energy sources, both for economic and environmental reasons, has led researchers to investigate the opportunities offered by the electrification of flight. However, fully electric designs are not viable in the foreseeable future, as the performance characteristics of the electric devices are still not comparable with the achievements of fuel-burning propulsive systems. A proposed solution is to electrify only a fraction of the aircraft system while the technology maturity level is still advancing. The use of two energy sources opens the design space and allows for the experimentation with novel aircraft configurations that could lead to interesting energy consumption reductions. However, established methods for aircraft design become obsolete as the required complex configurations and control strategies cannot be modelled. Therefore, the objective of this project was the development of a conceptual design procedure that can be applied to size and analyse any hybrid electric architecture that remains simple enough to be usable at the start of the design.

Guillermo Ortiz Jiménez

Faculty of Electrical Engineering, Mathematics & Computer Science Guillermo obtained his master’s degree in Electrical Engineering. He chose a graduation project in the field of signal processing. He first dived into the topic of deep learning, a machine learning technique that teaches computers to learn by example. He examined whether he could extend classical deep learning techniques, meant to classify audio signals or images, to techniques useful for classifying signals supported by an irregular structure. Such learning methods can be used to classify complicated non-structured data such as measurements from body sensors. Guillermo managed to quickly develop a graph-convolutional deep network structure, which successfully classified the irregular signals. Guillermo also tackled the topic of sparse sensing, a technique to reduce the number of sensors in a sensing system. He established a complete sparse sensing framework. His work can, for example, help movie recommender systems (such as Netflix) to pick movies and users in a clever way to predict all preferences. Guillermo is the first to introduce such a framework and his work is truly ground-breaking. A conference paper has already been accepted for one of the main conferences of the IEEE Signal Processing Society. His thesis was rewarded with the highest possible grade (10). “With Guillermo you can always have very mature discussions and brainstorming sessions with interesting outcomes. He is one of the best MSc students I ever met.” Graduation committee - Prof. GJ.T. Leus, Dr S.P. Chepuri, Dr R. Hendriks, Dr D. Tax Thesis synposis In this new era of data science, Machine Learning (ML) and Signal Processing (SP) are becoming the key driving forces of the fourth industrial revolution. They are paving the way for the genesis of new disruptive applications across many fields, ranging from the biomedical sciences to the ICT and manufacturing industries. Most of the tools in ML and SP, however, can only be applied to signals residing on a regular grid, e.g. audio and image signals. In my thesis, hence, I extended these tools to signals that lie on irregular domains with a graph structure, e.g. traffic networks, 3D meshes, or social network graphs. In particular, I developed two mathematical frameworks: one for the classification of graph signals using tools from deep learning and one for their sampling. The applications of my thesis are diverse varying from brain signal decoding (classification) to the automatic recommendation of items in e-commerce (sampling).

Eleni Chronopoulou

Faculty of Architecture and the Built Environment Eleni completed her master’s degree Architecture, Urbanism and Building Science in the summer of 2018. Her thesis explores how landscape architecture has the capacity to work as an integrative common ground, bringing together conflicting notions such as natural and engineered, formal and informal, concept and reality, process and form, the designed landscape and the practices of everyday life. Eleni researched the landscape of Kifissos, a heavily abused river area in Athens, Greece. This area has become part of the city’s infrastructural network, functioning as a highway and a sewage collector. The once natural dynamic river banks are now replaced with strict concrete boundaries, expressing a conceived necessity to dominate nature. Eleni describes the case of Kifissos as oppositions of uncontrolled dynamic natural processes and an over-controlled landscape. The oppositions are addressed in her graduation work through an alternative reading of the existing landscape sustained by theory, in search for latent conditions of coexistence. Extracted from their habitual settings, Eleni translated these conditions into design concepts. This combination has resulted in a flexible landscape architectural framework that integrates social, environmental, and technical aspects. Her thesis was rewarded with the highest possible grade (10). “Eleni’s thesis is an outstanding contribution to the discipline of landscape architecture, combining theory and design in a clever innovative way.” Graduation committee – Dr Inge Bobbink, Dr Esther Gramsbergen, Alexander de Ridder MSc Thesis synopsis Kifissos is an abused urban river in Athens: a heavily polluted landscape suffering from deadly flood events that have been escalating together with the city’s growth. The river’s containment within concrete boundaries reflects a conceived necessity to over-control unpredictable natural dynamics, reflecting an opposition between man and nature. Furthermore, the unnegotiable linearity of the river results in one more division: between rich, formally designed neighbourhoods and poor districts which have grown informally, outside the control of urban plans. To address these oppositions, the design starts from an excavation on the existing site, investigating the common grounds between conflicting notions: between natural and engineered, formal and informal, the designed landscape and the practices of everyday life. The extracted conditions of coexistence are translated into design tools able to incorporate social, environmental, and technical aspects closely related to the realities of the existing milieu.

Half Height Horizontal

NWO grants funding for innovative research on physical experimental environments

How to move from experiment to mainstream? A consortium led by professor Tamara Metze, has been awarded a prestigious grant from the Netherlands Organisation for Scientific Research (NWO). In search for pathways toward more sustainable futures, Metze and her team will explore how various innovations in field labs such as The Green Village, in urban living labs such as Engy Lab South-East in Amsterdam, and in all sorts of citizens’ initiatives, can be mainstreamed and make more impact on sustainability transitions. Pilot paradox The project ‘From EXperiment to sustainable change: TRAnsformative methodologies for Innovation and learning’ (EXTRA) seeks to overcome a persistent “pilot paradox”. In this paradox, much experimentation takes place but long-term systemic impact remains difficult. Researchers together with all sorts of change makers will synthesise existing knowledge on how to mainstream, upscale, spread, broaden and deepen developed innovations. Tamara Metze: ‘I am excited to unravel what are effective ways of cocreation that lead to mainstreaming the positive changes made in experimental environments. We will figure out how learning and innovation can lead to lasting changes in regulations, policies, and financial systems and the biophysical environment.’ Tamara Metze Read the NWO press release Actionable tools The project is crucial for accelerating sustainability transitions. By refining methodologies for mission-driven experimentation and develop hands on tools for all sorts of change-makers, it will be easier to mainstream the sustainable lessons and innovations. ‘These tools will not only aid grassroots innovators but also influence institutional and organisational structures, ensuring that lessons learned from experiments are better anchored in policies, regulations, and organisations’, explains Metze. The project will employ a transdisciplinary action research approach, bringing together knowledge from various disciplines and policy domains. By co-creating solutions with public and private partners, the research will have an immediate impact. In the long term, the project aims to build a more efficient innovation ecosystem, contributing to more impactful and sustainable outcomes for both society and the environment. Projectpartners TU Delft, VU Amsterdam, Wageningen University & Research, Hogeschool van Amsterdam, Erasmus Universiteit Rotterdam, Hogeschool Rotterdam, The Green Village, AMS Institute; PBL Planbureau voor de Leefomgeving, WoonFriesland, Dijkstra Draisma, Provincie Noord-Holland, Ministerie van Binnenlandse Zaken, PRICE / Almere, BouwLab, Alliantie Samen Nieuw-West, Innovation Quarter.

Unusual waves grow way beyond known limits

Waves that come from multiple directions are extremer than extreme. These remarkable deep-sea waves can be four times steeper than what was previously imagined, as is shown in research by TU Delft and other universities that was published in Nature today. A long time ago, stories were told of mysterious rogue waves that materialised out of nowhere and could topple even the largest ships. These waves lost their mythical character when the first rogue wave was recorded at the Draupner platform in the North Sea. In 2018, Ton van den Bremer and his colleagues at the Universities of Edinburgh and Oxford managed to recreate the Draupner wave in the lab for the first time ever, and this opportunity to study freak waves closely produced unexpected insights. Multiple waves push up water New research by the research consortium now shows that these remarkable waves do not break when traditional theories hold they should, the secret behind which lies in how they arise. Ton van den Bremer, expert on fluid mechanics at TU Delft and led the study, explains: “When most people think of waves, they think of the rolling waves you’d find on a beach. The type of wave we studied occurs in open water and arises when waves coming from multiple directions come together. When these waves with a high directional spread converge, the water is pushed upwards, forming a partially standing wave. An example of this is known as a crossing wave. How crossing waves arise Under certain conditions at sea, waves from multiple directions occur. This can happen in a place where two seas meet, or where winds suddenly change direction, as in a hurricane. When waves from two directions meet, a cross wave occurs, provided their directions are far enough apart. The study also shows that the further apart the directions are, the higher the resulting cross-wave. Travelling waves break when they reach a certain limit, this is when they reach their maximum steepness. The study shows that waves with a multidirectional spreading can get as much as 80% steeper than this limit before they start breaking, which means they can get almost twice as high as ‘normal waves’ before they start to break. Travelling wave (l) and a wave with high directional spreading (r) Breaking waves that grow Next, the researchers found another highly unusual phenomenon that defies existing theories, a phenomenon that is unprecedented according to Van den Bremer: “Once a conventional wave breaks, it forms a white cap, and there is no way back. But when a wave with a high directional spreading breaks, it can keep growing.” The study shows that these enormous waves can grow to twice their original steepness while breaking, which is already twice bigger than the conventional limit. Together, the waves can grow four times steeper than previously thought possible. Damage to offshore structures The knowledge that multidirectional waves can become as much as four times larger than was deemed possible can help design safer marine structures. "The three-dimensionality of waves is often overlooked in the design of offshore wind turbines and other structures in general; our findings suggest this leads to designs that are less reliable", says Mark McAllister of the University of Oxford, who led the experiments and is now a senior scientist at Wood Thilsted. Innovative vertical sensors made it possible to take accurate 3D measurements of waves. Innovative 3D measurement method A 3D measurement method developed in the FloWave lab paved the way for these new insights. “Conventional 2D wave measurement methods weren’t up to the task”, Van den Bremer explains, which is why the research group designed a new way to create 3D wave measurements. Ross Calvert of the University of Edinburgh: “This is the first time we've been able to measure wave heights at such high spatial resolution over such a big area, giving us a much more detailed understanding of complex wave breaking behaviour." FloWave Ocean Energy Research Facility in Edinburgh. The circular basin has a diameter of 25 metres and can be used to generate waves from multiple directions. Header image by: Fabien Duboc

Ensuring safe and quick food bike-delivery services in cities

Cyclists rushing to deliver food on time to hungry customers is an increasing problem in cities with the growing demand for fast home delivery services. This surge has resulted in more traffic in bike lanes, contributing to accidents and raising concerns about rider safety. In the framework of SINERGI project researchers like Yousef Maknoon are looking into solutions that will help boost logistic operations that are both efficient and safe. ‘Bike delivery services are a great way to transport goods from A to B in a green manner, replacing delivery cars or vans. These micro-delivery systems can really help make city logistics more sustainable,’ says logistics and modelling expert Yousef Maknoon, who is involved in developing real-time decision models for the SINERGI project. Besides looking into sustainability, the project aims to empower delivery providers to offer cost-efficient services, while prioritising the well-being of riders. ‘We want to help bring down the number of accidents,’ stresses Maknoon. Private and public stakeholders have joined to conduct pilot initiatives in the cities of Amsterdam, Shanghai, Singapore and Copenhagen. Yousef Maknoon Safe routing ‘To improve rider safety, the app automatically provides recommended routes when food delivery riders receive their task, helping them avoid dangerous intersections and busy streets. In Amsterdam, the goal is to develop a map that will show the safety of cycling infrastructure. The map is planned to be enriched with real-time information such weather conditions, busy days, and times of the week to not only improve delivery time prediction but also assess route safety in real time,’ explains Maknoon. ‘But everything depends on the cyclist's willingness to take the safer route. When a rider is paid per delivery, they might not be willing to take a longer route. Especially when they know the area well, it can be tempting to take a shorter route that may not always be the safest option.’ A survey held amongst 300 delivery riders found that they can be nudged to follow the recommended routes when they are compensated financially. Profit versus safety Maknoon: ‘What we also found is that paying an hourly fee, instead of paying per on-time delivery, promotes safer riding behaviour, like Just Eat Take​away does in the pilot in Amsterdam. However, other issues arise because riders might not be so motivated to deliver on time. Then you need other incentives to motivate efficiency among riders. Otherwise, customers might switch to other service providers. This puts the business model which is based on hourly payment and prioritize safety, under pressure.’ It seems now that delivery services need to make a trade-off between profit and safety. ‘With the SINERGI project we want to empower delivery providers to offer cost-efficient services while prioritising the well-being of riders.’ Government regulation Public authorities can, for example, improve road safety by enhancing infrastructure, such as building separate bicycle lanes.’ Delivery providers can introduce incentives for riders that compensate the extra time a longer, but safer, route might take. But this puts pressure on profitability and could cause micro-delivery logistics platforms to struggle or even go out of business. It is likely that government regulation will need to play a role in profit-driven societies, as safety risks being overshadowed. Fair delivery system This is also the case for ensuring a fair delivery system where all customers are serviced, whether they live in the busy city centre or the less densely populated countryside. Otherwise, customers who live farther away may not be serviced, as longer cycling times mean less money for riders when they are paid by commission. Riders can simply reject these orders and choose to deliver only to places where they think they can earn more. Human factor In this digitally connected world, we need to consider the human factor in real-time decision-making. The wellbeing of riders, their working conditions, and their quality of life are also important when we talk about making operational decisions. It is interesting to compare the four cities and how they manage the tension between cost-efficiency and safety, and to see what they can learn from each other. About SINERGI SINERGI is a three-year project that runs from 2023 to 2026. It involves thirteen research institutions, governmental authorities, and companies collaborating on a comprehensive framework to improve sustainable city logistics. The project aims to enable real-time management and strategic planning of efficient, safe and user-friendly delivery services. Besides Yousef Maknoon other researchers from TU-Delft involved are: Shadi Sharif Azadeh (project leader), Gonçalo Correia, Kuldeep Kavta and Dongyang Xia. Read more about the SINERGI project.