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I am a 43 year old Dutchman and still a student (eek). When I say “still” I actually mean “again”. I used to work on ships all over the world for about 15 years but eventually gave up the seafaring when I met the love of my life, a beautiful Cork woman. I moved to Cork and decided that an engineering PhD in UCC would be the perfect pastime for all that free time I suddenly had on hands. Last October I proposed to said Cork woman and she, foolishly, agreed to marry me. That made me an extremely happy puppy!

I’m guessing most of you have seen big wind turbines on land (renewable energy, yay!), but now imagine that same wind turbine on a floating platform out at sea. It’s being battered by waves and wind, and current is dragging at its anchor chains. Safe to say that if the platform moves around a lot it will not be very healthy for the lifespan of the turbine. So if we are designing a platform for a floating wind turbine it has to be very stable.

Now before we put a very expensive turbine on a platform in the sea we want to know how much it is going to move around. To get an idea of this we first make a lot of very complicated calculations, or better yet, let a computer take care of all that tedious stuff. To check these calculations we build a small replica of the floating wind turbine (which is of course a lot cheaper to build than the real-life version) and put it in the wave pool.

The wave pool in the lab I work in can create waves, but we want to replicate all the conditions at sea so also wind and current. Unfortunately, the lab does not have machines to make wind and current. So how do we replicate all the conditions at sea?

That is what I am working on at the moment. To replicate wind I am sticking a drone on top of the model where the turbine blades would normally be.

Okay, let’s think about that for a second…

It’s a floating wind turbine, not a flying wind turbine, right? Correct! If I spin the propellers of the drone gently in the direction the wind would normally come from, it will move the model around the same way as the force of the wind normally would. Obviously I don’t want to spin the propellers too fast and lift the model out of the water. So I let the computer make a lot of tedious calculations for me again to tell me how fast I should spin the propellers. Lo and behold, we have wind!

For the sea current I let the computer calculate how hard the current would tug at the platform, but instead of actual current I let a pair of small winches with cables do the tugging on the model.

There you have it folks, that’s how we simulate wind and current in our lab. This method is called ‘hybrid testing’. We now have a cheap way of testing if a floating wind turbine (or any other floating object) will behave at sea the way engineers had designed it to

This is the drone that sits on top of the model. I tinkered with it a bit so it doesn’t look like a typical drone anymore

Here you see the model in the wave pool. The drone sits on top of the mast.