Ships aren’t the only structures to have a hard time at sea. The emergence of offshore wind farms has only increased the need for knowledge about the impact of waves on maritime structures. Peter Wellens is an expert in this field. He wants the results of his research to be shared as quickly and as widely as possible, with other researchers as well as with the industry.
For Peter Wellens, it’s a matter of safety. Some 50 ships are lost to the ocean floor each year. While this is a lot less than at the start of this century, when set against the ever-increasing size of ships, this amounts to a tremendous amount of material damage, not to mention the loss of human lives. “If similar numbers of passenger planes crashed, all hell would break loose,” he says. Although the exact course of events leading to a shipwreck is sometimes difficult to ascertain, wave impact often plays a significant role. “The force with which waves hit a deck can cause structural components to break, or worse. This has to be made a lot safer. In particular, the bridge of the ship shouldn’t be at risk.”
Besides ships, the support structures of offshore wind turbines also have to withstand wave impact. “Wave impact creates accelerations elsewhere in the structure, which can cause components to fail,” Wellens explains. “The current calculation method leads to designs with heavy and therefore expensive steel structures. This is a limiting factor in the further development of wind turbines. Having a better understanding of those failure mechanisms will enable us to design more cost-effectively. And an affordable energy supply for everyone has now become a major social issue.”
In order to design more safely and cost-efficiently, more knowledge is needed, because wave impact is still a largely misunderstood phenomenon. “The variation in the strength of wave impacts is so great that no two impacts are the same. We also don’t know what the greatest force is that could be associated with such a wave impact.” Wellen’s ambition is to discover the truth behind wave impact, and he believes this requires a broad approach. “A single research method isn’t going to get me where I need to be. There are multiple approaches that have to work together optimally. That’s why I do experiments at both model scale and full scale, and I also develop numerical models. These complement each other. They are expensive and time-consuming methods though, so I am also developing analytical methods to predict the interactions between waves and structures. You especially need such rapid assessments in design projects, because of the time constraints in a tendering process, for example.”
The piece of truth that I expose will end up better with Open Science
Wellens is convinced of the importance of Open Science. “The piece of truth that I expose then becomes more useful. My research is comparatively close to the industry, and Open Science is a direct means of communication. As well as scientists, I try to reach designers, shipyards and consulting agencies. We have a thriving maritime and offshore industry in the Netherlands and I hope my research will contribute to what they are doing,” he says. “For example, I put the data from my experiments online. I am also developing a numerical method, which will be put online once it's sufficiently reliable. All the related documentation will also be put online eventually. I hope that people in the industry will be able to work with it immediately, or at least know how to find their way to us if they have questions.”
Aren’t there any objections to the fact that it's not only the Dutch maritime industry that has access to the research results? “That is sometimes used as an argument against Open Access. It has been funded through Dutch taxpayers’ money after all. But you also share your work internationally when you publish the old way, so that’s not a characteristic difference," Wellens believes. “However, there are organisations that use Open Access as a profit model. In that case, there’s a conflict of interest, because quality is no longer the only indicator. In the Netherlands, the Association of Universities in the Netherlands (VSNU) has paid off the costs of open publishing through major publishers. This hybrid model is the best of both worlds. Quality remains the most important indicator, while articles reach the widest possible audience. I’m a big proponent of this hybrid model.”
However, not all research results may be published openly. “When you collaborate with businesses, you have to make good agreements about what part of the research should be kept confidential. You have to consider what is patentable and what is sufficiently open to publish. You have to make good agreements about this in advance, and you might have to discontinue the collaboration if you can’t agree,” says Wellens. “Everyone’s interests must be served after all, and it’s in my interest for information to keep flowing. Publishing provides feedback and new insights, which I in turn can learn from. I do notice that companies are becoming more understanding about the fact that we want to publish results.”
Developing a basis for comparison
Something Wellens would like to see change is how impact is measured. “In other forms of academic literature, the citation index is an indicator. When the industry cites your research, this is done in reports. An open access article can be used much more, but an index that says something about Open Access is still lacking,” Wellens says. “I hope to see an indicator developed that enables us to show that Open Access sharing with the industry leads to more direct use of the methods we develop and the results we generate, and to more appreciation for researchers. That is my wish.”
If you collaborate with companies, you must make clear agreements about which part of the research must remain private’
Wellens expects to need many more years of research to fully understand wave impact. “Perhaps it’s meant to be. My name is Wellens after all,” he says, referring to the German word for wave, Welle. Meanwhile, he also enjoys preparing the next generation of maritime engineers for their careers. “It is a privilege to work with young, ambitious people. Giving them some guidance, a little push in the right direction or slowing them down a bit to help them achieve their goals” It earned him the title of the faculty’s best lecturer in 2021.
He is most proud of his work with graduating students. “That’s quite a complicated role. You need to help a graduating student and contribute to the project, while at the same time keeping enough distance because you’re the one making the assessment. You have to be clear about those two roles from the start. Actually, that is harder than lecturing; I also feel that you have a bigger impact when you guide students towards graduation. That’s what really gives me job satisfaction.”