'Sailing'?? Directly to Windward

Certainly agree with that to a certain extent. As you say sailing market is not a moneyspinner. Yes, patenting is something of an ego thing. You don't necessarily have to go through with the whole thing. The initial application, not very expensive, is enough to get you on the databases, and therefore you are recorded in history as the originator of the idea! An ego thing - probably.

 

So being recorded as the originator of an idea is good for the ego even when you were not the originator?

Strange world...

 

If you are the originator then you should be accorded some credit. But it wouldn't be right to take an idea that is already in the public domain. The patent process is supposed to filter out stolen ideas.

 

Hi,

In August 2008 I saw this on land in Den Helder in Holland . . . . . . . .



Just tracked back some info.

There seems to be a lot of knowledge about the turbines at the university teams in those contests, maybe some their turbine technology can be used for boats . . . ? ?

http://www.inventus.uni-stuttgart.de/

http://www.spiritofamsterdam.nl/

http://www.sciencedaily.com/releases/2008/08/080827104702.htm

http://www.popsci.com/node/32069

http://www.gizmag.com/the-first-race-for-wind-powered-vehicles/9953/

http://en.wikipedia.org/wiki/Wind-powered_vehicle#On_land

http://www.spiritofamsterdam.com/assets/2010/Race-Report-2010.pdf

http://youtu.be/IWNEXBBAGNw (June 2008)

Good luck!
Angel

 

This land cart competition is very interesting. It would be good if they could do one for boats also. Maybe it could be suggested to the organisers?

 

Just added this link to my above post...

‘‘ http://youtu.be/IWNEXBBAGNw (June 2008) ’’

Cheers,
Angel

 

World record speed on land on wind power only is now 74.5% of the wind speed while driving straight against the wind.

Racing Aeolus 2011

World record; august 18, 2011

From: wind energy events 2011

I'll guess on 90° to the wind they go really fast . . . . . . . . . .

Cheers,
Angel

 

High Tacker (www.damsl.com)

Angel

I think your guess is wrong about speed of these carts at 90 degrees to the wind. My guess is that, like wind turbine boats, they don't do much better on other points of sail than they do straight into it.

If the turbine can be made to act as an efficient propellor, then driven by the wheels of the cart, it's possible for such a vehicle to travel directly downwind faster than the speed of the wind. There has been quite a bit of discussion on other threads about DDWFTTW. But, to my knowledge, no vehicle powered by a wind turbine has yet come anywhere close to what land yachts with fixed sails have done across the wind.

Somebody please correct me if I'm wrong on any of this.

Cheers, Tom B.

 

What makes me think driving on 90° to the apparent wind is faster than straight upwind is that the wind power that drives the turbine on 90° is not against the travel direction, also on 90° the turbine will have much lower longitudinal drag on the vehicle's travel direction.

But this is just my guess when looking at them . . . . .

Cheers,
Angel

 

My bet it that High Tacker is right.

A turbine style cart can potentially go faster than the wind provided that it can be converted from turbine mode to where the wheels provide power to the rotor acting as a pusher prop. However, a fixed wing cart (such as Greenbird) should retain an efficiency advantage, and it is less likely to run into mechnical limits.

 

Far as I know part of the competition is a race of several rounds on a track where all directons of wind have to be dealt with. This exclude all vehicles that can't go straight upwind. On the track a vehicle that could quickly reverse from 'wheels driven by turbine' to 'prop driven by wheels' sure has an advantage on the straight downwind parts that could make them win the race.

I think someone should send a link to this thread to those teams . . . .

The links to the other threads are in post#4.

Cheers,
Angel

 

OK, the message is out, if they read each others website incl comments the other teams can know too...

See comment 16/10/2011 8:13pm down below the page.

Hi wind powered vehicle guys, if you visit, feel free to post

Good tips in post #98 & #100 to start with . . . . .

Good luck!
Angel

 

One observation: I suspect the high starting torque benefits of multiple ( >3) blades are negated in a watercraft because fluid flow over the propeller gives the wind turbine a kick start as the boat initially drifts downwind.

 

High Tacker www.damsl.com

Is everybody educated now about sailing directly to windward?

Not much action on this thread lately. Does that mean that all the members of this forum now believe and understand that it is possible to sail straight into the eye of the wind? Anybody out there still insisting that it isn't true and proper sailing, that it's powering with a wind machine? Anybody who doesn't understand that a simple sailboat, uh, a conventional sailboat, is a machine powered by the wind? The simplest and most ancient, primitive kind of a machine, with the mechanical advantage of an inclined plane, a wedge, like a chisel, a hatchet or a tomahawk? That there is no lift vector upwind? That nothing gets sucked upwind? That a conventional sailboat has the mechanical advantage of a ramp created by the keel, a ramp in the water inclined upwind and up which the sail pushes the boat, pushes it mostly sideways against the ramp, a highly stressful job, so it complains all the way and wants to roll over and ROTATE?

http://en.wikipedia.org/wiki/Simple_machine

A wind turbine boat is a more sophisticated machine that makes use of levers, wheels, axles, and a SCREW, and a screw is simply an inclined plane twisted into a spiral, a helix. A wind turbine boat has sails (airfoils) and prop blades (hydrofoils) perfectly analogous to sails and keels on conventional boats. The difference is that they rotate.

Sailors who don't understand, simply FEEL that there's a difference in sailing on a conventional boat, because, on any given point of sail, there are no moving parts, rather, the whole boat moves. Nevertheless, it is a machine, but it has only that one mechanical advantage, the plane in the water, created by the keel and inclined into the wind, a ramp upwind.

The only leverage involved with a conventional sail pushing a keel is to the advantage of the wind, NOT to the boat or the sailor. The wind turbine boat shows what you can do when you take advantage of all that leverage by letting the sails rotate around a wheel and drive axles and a screw, a prop, i.e., take advantage of all those simple machines, not just one.

The simple sailboat must tack, and thus makes a 2-dimensional zigzag track in order to get directly upwind. But it DOES get directly upwind, doesn't it? Is it getting something for nothing? No. It is powered by the wind, and it has a little bit of mechanical advantage, enough to change the direction of the wind's force. Indeed, that is the definition of a machine, that it can change the direction of a force.

A wind turbine boat makes a 3-dimensional spiral track, no tacking. If you still can't visualize how that is "sailing" straight into the eye of the wind, you can see some diagrams and read an even more longwinded explanation at:

www.damsl.com To your right on the welcome page, click on "Wind Turbine Rig"

And is there anybody left who believes it impossible to go downwind faster than the wind?

See http://www.fasterthanthewind.org/

Those guys have proved it possible. And now they are supposedly working on going upwind faster than the wind. I've learned to be very careful with use of the word "impossible", so let's say I'll be very pleasantly surprised if they are successful. Jim Bates's catamaran (see my posts above in this thread) could do 55% of the wind speed, for example, 11 knots straight into 20 knots of wind. These land carts shown above have now done almost 75% of the wind speed, straight into it.

To answer that last post by lumberjack_jeff: Once more about multi-bladed turbines, and especially such a turbine without blade twist:

There is no benefit to high starting torque if, after it starts, the turbine is inefficient. Yes, going to windward you get more wind, but that doesn't mean that you can afford inefficiency, rather, MORE efficiency is what you want. With increasing wind speed, drag increases faster than lift. You will not go nearly as fast to windward with a multi-bladed turbine as with a 3-bladed one. Too much drag PERIOD. And in high wind speeds, you won't be able to go into it at all, whereas with an efficient turbine you can vary the pitch so that you are letting most of the wind pass through, and you can still make headway. Of course, there's a limit, especially with respect to sea conditions. But you can accomplish the ultimate in heaving to, essentially hovering, barely making headway.

A 2-bladed turbine would be even better, but, because of substantially greater wind speed at the top of the swept area than at the bottom, an even number of blades gives much more vibration and noise.

As I've said in previous posts, Jim Bates's boat could sail straight into the wind, or in any direction, at just over 1 knot boat speed in 2 knots of wind. In less wind than that, to get it started, you could "kick" start it yourself.

You could go up on the bridgedeck, grab a blade and give it a fling, and then another and another, and row the boat along, straight into the wind or in any direction. And if there was true wind approaching 2 knots, rowing into it gave increased apparent wind to get the boat moving.

If you needed to go in reverse into the wind, you could just put the prop in reverse and sail straight backwards into the wind. Or you could "row" the boat in reverse.

 

Surely no.. It's just popping up again and again every now and then and repeats itself to the infinity and back.. or something alike