Back Story: WET Wings

The story of WET Wings

My first Great Idea happened in ’85-’86.  I had a small printing business and went out sailing over Easter – on the way home, with a moderate sea running, I was looking over the stern at the water rising and falling.  I got an image of swim flippers being held in that alternating flow and saw thrust being generated.

That would have been just another unimportant idea – inventing was a bad habit, I had Way too many good ideas – all the time – it was annoying. But then fate intervened – at the mooring I misjudged a jump from the boat and landed Very badly on the dock, it broke bones in both heels.  Hence, having involuntary excess time – I couldn’t move from lying down, had to crawl to the toilet lol… Over the next month, I developed WET Wings, it stands for Wave Energy Thrust.

WetWings was a totally new conception for wave energy devices – it used wings to generate power from ocean waves directly using hydrodynamic forces rather than the essentially hydrostatic forces normally used. It’s based on the simple properties of symmetrical aerofoils: A horizontal wing will generate positive thrust when moving through waves provided it is somehow constrained from moving vertically.

An existing example of this principle is the vertical axis, ‘egg beater’ Darius wind turbine design, which works exactly the same in essence.  I just unwrap the circular path of the wind machine to a linear path and swap the steady wind flow for an oscillating flow caused by waves.  So I imagined multiple wings distributed over the length of a long body  to “average out” the vertical forces and produce relatively steady trust.

I had a wonderful breakthrough moment when I thought of the rotor arrangement.  At this stage it was all still purely theoretical, a symmetrical wing Should generate thrust I was confident, but only when constrained – yet moving – and moving fast if you’re using a small wing (because of Reynolds Numbers)  – it seemed impossible for me to test with my tiny resources.

Then I had an ahah moment when I imagined flipping half a wing to point in the opposite direction and putting a bearing in the centre, like a zero pitch propellor…  I put a rough version together in less than an hour – and was absolutely delighted when I jiggled it up and down in a bath tub full of water and it did exactly what the physics said.  It spun VERY fast and, of course in the same direction whether I pulled or pushed it.  When I made a nicely shaped and very strong version I discovered that a lot of power could be transformed into fast rotary with a just few grams of hand-shaped wing.  Amazing amounts of force could be applied and it would just become a blur and make snapping sounds when a wingtip broke surface.

When you calculate the power per kilogram of these devices it is astronomical compared to hydrostatic designs – And it gets bigger the smaller the device, with the provision that small wings have to be moving faster to work.  It’s like the opposite of the normal scaling rule.  Wings are unusual in that when you scale them the aerodynamic load scales by the same factor since it’s not determined by volume but by area.  So the engineering related to lift loads of a wing doesn’t need to change when it is made bigger or smaller – and because in water you can support any gravity loads with buoyancy, it meant that Wet wings were scaling factor free.  Interesting coincidence of forces.

To demonstrate the linear version I got a bunch of rotor blades from a local agricultural helicopter maintenance business (for a case of beer 😉 and 16 metres x 100 mm x 100 mm x 2 mm wall, high tensile steel pipe, chopped the blades into one metre lengths, stuck them on the pipe in 8 pairs all in the horizontal plane with their leading edges pointing the same direction.

It worked even in virtually invisible non-waves, ghosting along at about half a foot per second – even inside the marina.  At this stage I still thought that, like a Darius rotor it would need a starting push off so I wasn’t expecting movement and couldn’t explain it on the spot to the ‘Scientific Observer” (He later used that to attempt to discount any validity to my ideas in his report).  What proved it for me was that when it was released in a mild chop it would accelerate strongly but my “automatic” depth regulating system failed and so it would always trend down and every time we’d watch it do this steady dive till it went out of sight below a metre or two.  Then it would stop, slowly surface, level itself and take off again.

I developed many conceptual designs for rotary energy systems, control systems for linear etc, etc.  It’s an invention that leads to many potential products.  I had many AhHa! moments designing the control systems and mechanisms.

It all came to a sudden halt in the October crash in ’87, (for added irony it was on my birthday). We were on a deadline for filing all the national patents from a PCT that was expiring and needed about $200,000 for lawyer fees etc and were offering 10% equity (We still had 85%) for one million.  We were going to get it.  Then suddenly we weren’t…