Direct Upwind Sailing

The windmill boat sailing directly upwind has the advantage that it does not have to tack. It need not sail as fast as a tacking sailboat because the distance it has to sail is less. So it may reach
an upwind point before the tacking boat, which will also lose speed in the tacks. The model boating pond at Norwich UK was constructed for model boaters in the 1920s it does indeed include
a water level higher than the concrete path surrounding it. This enable the models to be placed in the water easily. https://lh3.googleusercontent.com/p/AF1QipPM-muixFSOHUMZRiXYGsaPr3ePo5KIdE2YT2s=s680-w680-h510

 

While I am not an advocate of windmill powered boats, they look ugly and awkward, taking up deck space and are likely noisy when scaled to a useful size, but I would gladly experiment with one and support the modeling and thought experiment. I could even entertain the idea that they could supplement a more traditional drive on a commercial vessel. What I'm reading is a whole lot of, "it's a waste of time to pursue this concept." The why's are not even part of the presentation of this concept. OK, it won't scale, maybe. OK, the modeling and example could be better controlled, or more real-world, or more scientific or more information given, but is that what seeing a video of a windmill driven model boat making its way into the wind really calls for?

Wind speed at the water's surface is obviously not zero or there would be no ripples in that pond. Some of those videos show a fair amount of wind driven surface agitation. Arguing that windmill driven boats are no good because they would never stand-up to a rough sea in a blow is like saying ski boats are not worth manufacturing because they would be impractical to take from Cape Code to Gibraltar. OK, maybe so, but what does that have to do with the success of the demonstrated video?

Sorry people, but I think it's not just cool, but holds possibilities that stimulate my imagination. Those videos do not anger me.

-Will

 

Viewers of this thread should be reminded of the Brennan Torpedo. This was a torpedo which was powered by a force pulling in the opposite direction to its travel. The Brennan Torpedo https://windthrusters.net/Brennan.html substitute the backwards force for the wind and you have the direct upwind boat.

 

You should look at the Brennan Torpedo here: Pulling Backward To Go Forward: The Brennan Torpedo Explained https://hackaday.com/2024/12/17/pulling-backward-to-go-forward-the-brennan-torpedo-explained/ you will understand that a propeller can act as a fixed attachment point. Also here: The Brennan Torpedo https://windthrusters.net/Brennan.html

 

And don't forget Kevin Costner "Waterworld" reefable VAWT Orma60 .
I remember Polish popular science book , there's proposal of big ocean going hydrofoil catamaran ,propelled by big swivel mounted almost vertical axis , gyroplane propellers , four of them connected to in-the-wing jet pumps.
Theres was Australian made big windmill cat , noise was biggest concern . Kind of tripod was a propeller support .

If I consider such of design :
Wide cat , variable pitch windmill and propeller also , wide spread gearbox . Variable mill blade lenght will be nice but more complicated .

 

Just like a kid's yo yo will do when set on the ground and you pull the string. The yo yo rolls away from you when you pull the string to you. It's because you aren't pulling the yo yo to you, you're causing angular torque that can drive the yo yo away from you.

-Will

 

You are confusing work with force. at no time does he say that work (power) is increased. But force is multiplied by the leverage principle. If you study the Brennan torpedo you will see that it worked by pulling a string attached to a propeller which propelled the craft in the opposite direction. So that is proven. As they used them for 20 years. You got it the wrong way round - the thrust of the propeller is greater than the drag of the turbine. I will not go on about the other obvious way you misunderstand it. Only to say that the model was constructed to show it in real life. You cannot argue with the diagram because the model proves it works. It proves that a craft or body can travel in the opposite direction to the force that powers it (which is something you cannot believe) and that the weaker force from the turbine can be converted into a stronger force at the propeller. Note the use "force" and not power or energy. You clearly know nothing about leverage which is something that you see around you all the time. In this case it is the second class lever which applies.

 

As you note, those aren't particularly good boatspeed figures from that test.

 

Huh. This again....

 

I prefer the modified carbutetor that makes a car run on water.

 

Yeah. Now that has practical applications

 

We are aware of the concept of upwind VMG and pointing angles.

 

Think, is the fact that you happen to have the same fairly rare craft as one of the people you are quoting a coincidence? It seems unlikely that there are two Hawke Surfcats in Norwich, both owned by people interested in promoting windmill wind power.

If the devices you appear to work on work so well, why don't you enter a race and video it, so we can get independent objective proof of their performance?

 

You are completely misreading him. JE referred to the fact that there is no proof that windmill craft can scale "to any size", and the problems therein. You then moved to a different subject, which is the fact that small windmill craft - ie not craft "to any size" - can work.

As JE said, there is no proof of your claim that windmills work "to any size".

 

Windmill probably will be more effective if diameter incrasing . You're scepticall about windmill boats . There's no dedicateted hulls created especially for windmills . There's no researches of windmills dedicated to use as direct power converter for boat . There's no special low friction , variable ratio transmissions designed and no special 50 kind of propellers designed for.
That's possible that all these small details will make no braktrough but can make significant difference .