Behind the PhD-degree – Maarten van de Griend

About a hundred years ago, the Austrian forester Viktor Schauberger built logging flumes and other nature inspired applications with water. Drawing his inspiration biomimetically, he believed that nature would do things the best way. Like drawing air into the water through vortices. And now, it would take a team of water technologists, slow-motion cameras, and the efforts of an astronomer to unravel the workings of this new aeration method. Researching a shower head and water tornado in the process. This is the story of about-to defend PhD student Maarten van de Griend.

The people behind the science, and the science behind the people


Forester turned inventor Viktor Schauberger saw the elegance and efficiency of nature when he designed and improved a sort of slip-and-slide for cut down trees. This 1922 feat of engineering was a first in the area and it would be a sign of the success for Schauberger that had yet to come. He saw the value of the way nature handled its environment and water and broke his head over energy generation from water, purifying water and many other questions that eventually led to patents and commercial applications.

That is, some mysterious theories remained. There were many claims surrounding the properties of vortices and what good they could do to water. It would take many decades before we got answers. Schauberger’s son Walter would eventually mathematically underlie the best shape to generate these water tornados in, but no one ever proved the physics behind it.

So there lay a challenge for a scientist. It would be one for Maarten van de Griend.


Though if you knew Maarten at that point in time, you would have never guessed that he would be the right man for the job. Not that he would not be qualified, but the route he took was unexpected. Van de Griend: “I think I must have been about seven years old when I did my class presentation on the solar system, from that age I knew I wanted to become an astronomer.” And so he did his studies Physics and Astronomy. But after finishing that: “I knew I wanted to do something more tangible. My parents are both engineers and I have a broader interest anyway. Doing good for the environment was another drive that made me end up at Wetsus.”

A big plus for choosing Maarten was his physics skills, yet unfamiliarity with the matter. “Schauberger has made a lot of claims. Being an ‘outsider’ allows you to be more critical of the matter. Back at that moment in time, the claim was not well researched yet at all, so it needed a proper start.”

The PhDer was to first characterize the vortex before he could apply and investigate it. That is, describe the vortex in all sorts of ways. For Maarten that meant identifying the way the water acted. “Depending on the velocity that the water comes in with, we could find three regimes – or shapes – that the vortex could have. Each with its own set up characteristics. We could measure the speed of the water at any point by injecting fluorescent particles and tracking them over time by illuminating them with a laser sheet. It allowed us to learn that there are secondary vortices that are vertical on the surface of the big one. It explained the heightened surface area and aeration.”

Further investigation of the phenomena saw its use in every-day environments. Maarten: “We researched a shower head that has a built-in vortex before distributing the water.” This time it was not the aeration that helped out, but the speed. “Though somewhat subjective, shower comfort has to do with the exit velocity of water drops ejected from the showerhead. By using the vortex motion, you can reach equal velocities, with less pressure and without reducing the nozzle sizes that can lead to clogging.”


The range of researches allowed Van de Griend to grasp a wider reach for his science. “Doing this PhD helped me communicate my research and get me to be a professional. I can say I’m no longer a theoretician, but an engineer, a water technologist now. An expert.”

And Maarten is not done learning yet. As researcher at CEW, he gets new projects every time and assists students in making the research take shape. It’s an even more applied setting. Maybe even more an engineer setting, but now he also has the exciting role to inspire the future generations as well.

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