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Graduation of Gijs Nannenberg

Graduation of Gijs Nannenberg 20 December 2021 14:00 till 16:00 - Location: CiTG - Room 3.02 - By: Webredactie River bed response to a changing hydrograph due to climate change Professor of graduation: Dr. Ir. A. Blom Supervisors: C. Ylla Arbós (TU Delft), Dr. Ir. R. Schielen (Rijkswaterstaat, TU Delft), Dr. T. Bogaard (TU Delft) The objective of this thesis is to assess the effects of climate change on the initial, transient and equilibrium response of mixed-sediment river. Climate change will cause changes to hydrographs, which in turn affects sediment transport capacity and thereby the river bed profile. In order to create a better understanding of the processes in play we analyse a theoretical situation using the Lower Rhine as reference. The river Rhine is a heavily engineered river. The exact effects of climate change are therefore difficult to predict, as human intervention is significant. A simplified version of the Rhine can however give an insight into river response to climate change. First an analyses of historical discharge and future discharge of the Lower Rhine was made, which gave an insight in the changes to the hydrograph that can be expected in the future. Next a model was made representing a theoretical river reach. For this river reach the upstream hydrodynamic boundary is varied and the results of these variations are analysed. Using the results of this model and the hydrograph expectations it was discussed what can be expected to happen to a river bed under these circumstances.

AI in port and maritime research in Leiden, Delft and Rotterdam

AI in port and maritime research in Leiden, Delft and Rotterdam From a ship that has been designed to tell you what maintenance it needs and when, to an intelligent journey planner for global goods transport. The three universities in Zuid-Holland are abuzz with AI research in the field of ports and maritime. Three researchers explain. Part two in a series of five about themes into which the three universities conduct AI-related research. ‘The big challenges facing ports are accessibility, sustainability and finding the right employees,’ says Rudy Negenborn, Professor of Multi-Machine Operations & Logistics in Delft. ‘In a busy port, you have to optimise your planning to avoid delays, congestion and unnecessary emissions. This doesn’t just require solutions to technical challenges: a solution can only be implemented if an organisation wants and has the right infrastructure for this.' 'We can develop technology that makes it possible for ships to enter a port safely and autonomously, so an operator only has to intervene in an emergency. But what would this mean for the operator’s stress levels? How many ships can they monitor at any one time? And would the ships interact and exchange information with one another?’ All expertise needed Negenborn has spent about a year and a half intensifying the collaboration with the universities of Leiden and Rotterdam. He can see how the expertise of all three universities is needed when working with many different parties on solutions relating to smart maintenance, smart transportation and smart logistics. ‘In black and white terms, Delft’s main strength is technology, Rotterdam’s is economics and business models, and Leiden’s is social and legal aspects.’ Black and white indeed, because Thomas Bäck from Leiden doesn’t fit this stereotype. He is the head of the Natural Computing research group at the Leiden Institute of Advanced Computer Science (LIACS), which is working on algorithms that apply principles from evolution and nature. A key question in his work is how an algorithm can weigh up different aspects, for instance costs and sustainability, before suggesting the best option. ‘This could mean the best way to design ships, but learning algorithms can also predict the best time for maintenance. This is something that Delft is also researching.’ How we can make a difference Bäck gained massive inspiration from a focus group with about ten participants from the three universities that focused on AI research in the area of ports and maritime. ‘We discussed how we could really make a difference, while taking the UN Sustainable Development Goals into consideration, for instance. We have to think about social aspects: regulation of AI and how it can explain itself better so as to win people’s trust. The economics and logistics perspectives from Rotterdam were also new to me. It was great.’ More collaboration in Zuid-Holland will create opportunities, says Rob Zuidwijk from Erasmus University Rotterdam. As Professor of Global Supply Chains and Ports, he can see chances to improve the efficiency of goods transport and ports. ‘I want to bring together the public, the city, researchers and not-for-profit organisations in society.’ What autonomous shipping means If it were up to Zuidwijk, he would invite all of the above to the campus to simulate the Port of Rotterdam in a digital twin environment. ‘Then they would see what autonomous shipping means and what impact certain behaviours have on the employees and public. This would strengthen the links between public and private stakeholders, both at the port and in the city. The dialogues with, among others, Rudy Negenborn and Mark van Koningsveld from Delft University of Technology are helping enormously to get a clear idea of what needs a digital twin environment must meet to get multidisciplinary research with an impact off the ground.’ Collaboration with business is hugely important if you are to have an impact as a researcher, and this is something all the researchers have plenty of experience of. With the Port of Rotterdam of course, and Bäck also works with companies such as Air France-KLM, Tata Steel and the Honda Research Institute in Germany. Negenborn: ‘If we three universities can scale up, it will be easier to reach the boardroom of big companies, which will mean bigger budgets to work with. This will make us more decisive.’ Below is an example of the work of each of the three professors: AI-related research in ports and maritime. Proactive ship maintenance: algorithm prevents damage and costs Delft University of Technology - Rudy Negenborn ‘You buy a ship for 30 years. In that time things break, at unfortunate moments. Being at anchor can cost tens of thousands of euros per day, and if a part isn’t in stock... Together with Leiden we are working on health monitoring systems in the Autonomous Shipping research lab (RAS). These kinds of system closely follow how a ship responds to the rudder, the engine speed and so on. ‘The algorithm collects and interprets this data. A sudden reduction in response to the rudder can be caused by sticks around the propeller. If the system suggests this diagnosis, a zigzag manoeuvre can solve the problem. The system can automatically decide whether to temporarily reduce speed, for instance, to prevent engine failure. ‘In this project we in Delft are working on ship dynamics: how to design a ship. Leiden is dealing with the data-science side: how and which data can lead to a diagnosis and advice from the system. A user-friendly dashboard is also coming from Leiden. We’re working on the algorithms together.’ An intelligent journey planner for goods transport Erasmus University Rotterdam - Rob Zuidwijk ‘Fresh cargo shouldn’t be kept waiting because the cooling system is running. If lorries drive in convoy, they can save as much as 10 percent on fuel. If they coordinate their trips, they can save even more. Inland shipping could be much more economical, but the best use isn’t always made of it. It requires more logistical coordination than freight transport by truck. What we need is a journey planner for European goods transport. ‘Where the 9292 [a journey planner for public transport] brings together all the individual timetables, our system has to be smart. It has to harmonise an enormous amount of data, recognise patterns and then suggest and organise the cheapest, cleanest and fastest route. If something goes wrong, like the recent Suez Canal blockage, the system has to respond. ‘With econometrics and computer science professor Rommert Dekker and professor of goods transport and logistics Lorant Tavasszy from Delft, I’m now thinking about such systems. We’re in talks with parties from the Port of Rotterdam. If the port provides data that show what is happening in the port and in the European hinterland, we can get an algorithm to learn from this. In future all the parties in the future will be able to organise the optimal transport on a virtual map and determine whether the contents of container X will arrive fresh.’ Algorithm shows: the best design and clean your ship in time Leiden University - Roy de Winter, PhD candidate supervised by Thomas Bäck ‘I’m researching efficient optimisation algorithms at C-Job Naval Architects and Leiden University. An important question is how algorithms can weigh up the lowest production and usage costs against the best quality and result. If, for instance, you make a ship long and slim, it will be more efficient, but you need more steel to build it than to build a shorter, wider one. And more sustainable materials and cleaner fuels are becoming increasingly important in the ship design process. ‘We are also analysing operational data from ships. We recently made a unique discovery. A client wanted to see the influence of the wind on the horsepower required and provided datasets for us to find out. We checked the data from two identical ships and saw that one was over 30 percent more economical than the other. The first one had just been cleaned, whereas the second one had a significant coating of algae and barnacles. That proved to be a significant cause of the difference. Cleaning can be a whole operation, but it’s definitely worthwhile! Nowadays there are methods to do this cleaning in water, with a kind of robot lawn mower, for example.’ Five themes packed with AI research in Zuid-Holland This article is part two in a series in which we show how teaching and research using or into AI plays a role at Erasmus University Rotterdam, Leiden University and Delft University of Technology. The articles will cover the five themes that the universities are working on, together and alone: Peace, justice and security Port and maritime Energy and sustainability Life sciences and health Smart industry Text: Rianne Lindhout

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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