Well done you Blackbird guys! I think the problem with a lot of your knockers is they have never sailed a high performance landyacht. I quite regularly sail my Class 5 landyacht at 5 times the windspeed in light winds (<5kts). Did last weekend in fact, no problem. Not directly down wind of cause, but we understand the principle.

My question is: If the blades of your propeller were like soft sails that you could sheet in to create a flatter wing section as your speed increased (like we do on our landyachts) would the propellers rpm accelerate? thus accelerate the vehicle?

now weve got the downwind bit sorted, how does it perform on reaches and more importantly , a broad reach.
I spend alot of time explaining to even experienced landsailors that you cant get sailing straight downwind and that you need to start ona reach , or even upwind when the winds are light.
what the the characteristics of your machine in other directions

cisco said...

landyacht, those are the experiments to be done after the DDWFTW experiment has been perfected.

Maybe a rotating propellor head, assiting foils, better mechanicals etc.

I think there is a long way to go with this one.

The one thing that concerns me is getting one's head swiped by that big prop.

I do believe these guys have hit on something here that will go a long way.

surely it doesnt just sail downwind, that would be silly

nebbian said...

landyacht said...
surely it doesnt just sail downwind, that would be silly

It would appear so...

Yup. As it stands the Blackbird is designed to go directly downwind faster than the wind. We have exceeded the wind speed on courses of 45 deg or so off the wind, but this is less optimal.

By making the entire rotor head swivel as suggested, and making the prop pitch variable over a large range, it would theoretically be possible to go faster than the wind in any direction.

So the boat with the big spinney thing on the mast uses a turbine, and can sail in any direction

Correct, but you cannot go downwind faster than the wind using a turbine.

Hiko said...
I take it that a turbine extracts power and a propeller delivers it ?

You got it