The Danish company Westrup A/S, which is one of the world’s leading manufacturers of seed-separation machines, was faced with a mathematical challenge. The company therefore contacted DTU’s mathematical flying squad.
Westrup was established by Troels Westrup in 1958 in his garage. However, the business soon outgrew its premises, and it’s not hard to see why. The company’s large halls are filled with heavy seed-separation machines, which enable farmers around the world to separate and process their seed better and faster. But even here, among experts with many years of experience, problems still arise that are not easily solved.
The seed-separation machines are based on advanced mathematical equations which explain how the machines function. The machines sort grain and seed by means of heavy metal crates which shake back and forth, separating the usable grain and seed from the everything else. Standing next to the machines, you can clearly feel the vibrations. And these vibrations spread to the buildings in which customers end up installing the machines. For many years, Westrup has been calculating the impact of these vibrations, but the company was keen for its calculations to be based to a greater extent on the latest knowledge in the area.
Collaboration benefits everyone
Associate Professor Poul G. Hjorth was able to supply this knowledge. As head of DTU Compute’s mathematical flying squad, he knows how industrial companies can benefit from cooperating with mathematicians.
In cooperation with colleagues and students, he set to work. He wiped a large blackboard clean, and together with the company’s own engineers, a couple of colleagues and a bunch of talented students, he performed new and complex calculations of the machines’ vibrations, and prepared a proposal for how the vibrations could be dampened by modifying the design slightly. The team then prepared a report, which was presented to Westrup’s technical manager, Flemming Dam. The company is now implementing the method proposed by the working group.
“The vibrations will never be eliminated completely. The two large containers which shake back and forth weigh over a tonne each, and are not aligned with each other so some vibrations are inevitable. However, we discovered that it is possible to eliminate the impact on the surroundings,” explains Flemming Dam.
“We also asked the mathematicians to calculate how best to optimize our machines to minimize their impact on the surroundings. And now we are working to apply the principle which the group came up with in our future products,” says Flemming Dam.
“"In general, collaboration between industry and the universities is a really good idea. There are about 100 of us in this company. And we don’t have the capacity to perform the calculations which Poul Hjorth and his colleagues can do. So it’s extremely valuable for us that they can help,” says Flemming Dam.
Help for industry
Poul G. Hjorth, Associate Professor at DTU Compute, is an expert in applied mathematics in industrial contexts, and he relishes the fact that industrial production is full of mathematical challenges. He leaps at any opportunity to go out and assist companies.
"It’s particularly inspiring to solve a mathematical problem when the product it relates to is something that enriches everyday life."
Poul G. Hjorth, associate professor at DTU Compute.
“As a mathematician, I think it’s very rewarding to see the role that mathematics can play on the factory floor. I find it very inspiring seeing these huge machines or whatever in action. As a technical university, DTU has both theoretical and applied mathematicians at its disposal, and it is from their interaction that innovation springs,” says Poul Hjorth.
And companies often call. Poul Hjorth has 20 years of experience at helping the business community solve difficult mathematical problems, giving him a wealth of experience to draw on. He uses this experience, among other things, to convince tomorrow’s engineers whom he teaches at DTU that everything they learn can be used for something.
“Our students sometimes ask why they really need to learn X, for example, because they assume that they will never need to use it. However, after working with all kinds of companies over the years, I have many concrete examples of how mathematics can be applied in the real world, including some of its stranger disciplines.”
Godfather to rare penguins
DTU Compute’s mathematical flying squad is a part of the international collaboration ESGI—European Study Group with Industry. Several times a year, the flying squad visits companies and uses mathematics to solve problems. Over the years, Poul Hjorth has collaborated with LEGO, Novo Nordisk, Danfoss, and countless small and medium-sized enterprises. Once, the squad even travelled to the UK to help a zoo with a specific problem.
“Through the ESGI cooperation, we were contacted by Bristol Zoo in England. They had a group of rare and endangered penguins, which they wanted more of. But no matter what the zoo did, they could not get the penguin eggs to hatch. Through the biologists and mathematicians working together, we found out that the eggs had to be rotated at a very specific speed—just as they are when the penguins stand with the eggs on their feet in the wild. We then submitted a report with our proposal to Bristol Zoo, and six months later they called and congratulated us on becoming godparents to a whole bunch of rare penguins,” he says.