'Sailing'?? Directly to Windward

During the event, which is between vehicles, we always talk about the efficiency of the vehicle and not just about a single component on the vehicle. The race scores are actually ordered by most efficient vehicle. The team with the highes efficiency wins the race (wind speed vs vehicle speed).

If the race was about the most efficient turbine than there would be no need to put them on a vehicle.

Bythaway i didn't make up the terms that are used in this event. It just is the way it is. Possibly it would be better calling it wind vs speed ratio or something like that, but it isn't.

 

Efficiency , in percentage, means the proportion of input to output. I think you have to be careful with engineering terminology if you want to be taken seriously

 

High Tacker www.damsl.com

Excuse me for butting in, but, Gonzo, there's no call to insult the guy over a question of semantics. There's obviously a bit of a language barrier here, but these guys are doing serious work. And it's obvious that when he says greater than 100%, he means a vehicle speed greater than 100% of the true wind speed. So apparently, in their specialty, that's how they define overall efficiency of the vehicle, i.e., if the vehicle reaches 100% of the wind speed, then the vehicle is considered to be 100% efficient.

I agree that such usage of "efficiency" will confuse some, but also want to say to SpiritAmsterdam not to take your nitpicking too seriously. They were invited to share information on this forum, so should be shown some hospitality.

 

I understand that its the organization dictating it, not you. But yes ratio would be much more accurate and less misleading term.

And High Tacker - I don't think that anyone is insulting here. Just that when you have 105% efficient machines lying around it will raise some eyebrows. And nobody is questioning the seriousness of the achievements and engineering feats done by the teams. The whole point Gonzo and I are raising that it will potentially take away from their credibility to use engineering term in incorrectly.

Edit: fixed HT's name

 

High Tacker www.damsl.com

kerosene

I resent that. I'm way more than 105% efficient when I'm lying around...and the only eyebrows raised are my girlfriend's, and she knows nothing about machinery...and of course doesn't take me seriously.

Cheers, and, while we're on the subject of getting the words right, the name is High Tacker, not Hightracker

 

I did not insult the guy in any way, but question his statement. Efficiency over 100% means creating energy, which violates the Laws of Thermodynamics. If true, it is a revolutionary design. If it is not, it means the claims are not to be taken seriously. Unless the poster takes care with the accuracy of his claims, we can't discuss them intelligently.

 

Well, they have to comply with NALSA rules for sailing records. They cannot use any stored energy for propulsion (even if it was stored during the run). I'm not sure but this might even rule out the usage of a variable transmission, because it potentially allows to use the rotor as a flywheel.

They had a fixed transmission on the DDWFTTW version. But when I see your race carts, the turbines spin really fast, even when the vehicle is slow. With a fixed transmission they will have to start rolling with a very slow rotor.

That is true, and yet the idea seems not as obvious as going upwind. There were even some physists who claimed DDWFTTW was impossible and would violate energy conservation. Have you encountered such positions regarding DDWFTTW among academics, or was it trivial stuff for them?

Good luck!

PS: There have been endless debates on this forum about whether such vehicles violate energy conservation, therefore some here are overreacting to the usage of the term "efficency" for "windspeed-ratio" because it might give people the wrong idea.

 

I don't think it is over reacting. If you mean windspeed to boat speed ratio, then say so. Efficiency is something different, even though related. That makes interchanging the terms confusing and misleading.

 

I would vote for a simple suggestion that "ratio" is more technically correct rather than pushing an entire crowd of innovative people that are actually doing something to change their terminology.

The choice of electric drive will be interesting to watch. To go from turbine shaft to generated AC through a power conversion system and then back to rotary power at the wheels with anything approaching the efficiency of a mechanical drive sounds like a real accomplishment. The use of a shrouded turbine also seems to be a technological advance.

Combining what they learn with what has been previously developed for on the water travel could actually make a difference. For the boater there is no rule that prevents adding a battery. Now you start getting into something that could be quite handy, especially for those keen on journeys along narrow waterways (such as the US Inter-coastal Canal).

A big side benefit would be the power available while at anchor.

 

P Flados: I am not sure who do you mean by " entire crowd of innovative people that are actually doing something to change their terminology." There are millions of people that use standard terminology worldwide. Are those who you are referring to?

 

Gonzo,

Those involved in using a wind turbine to drive a cart to windward of course. These appear to be people that are mostly young, smart and willing to do more that just post on the web.

There are a lots of dreamers and web surfers, but when I see people actually putting theory into action, I tend to cut them a lot of slack.

When was the last time you pushed the limit of what is considered state the art for a level of performance that is a real achievement in an openly contested public forum.

 

I've been racing since I was 12, so I can relate to that. However, bad terminology has no excuse and it causes misunderstandings. It can't be difficult for them to read a dictionary or get the definitions online.

 

High Tacker www.damsl.com

Uh, Gonzo, actually it's the ratio of output to input, so you got it backwards, and, according to the Laws of Thermodynamics, that ratio is always less than 1. So, within that narrow definition, greater than 100% efficiency is impossible.

But the word itself, "efficiency", has a history older than the terminology of the Laws of Thermodynamics. It's a word derived from Latin that meant a measure of effectiveness and the economy of time and effort. And nowhere is it written that the word cannot be used to describe the ratio of vehicle speed to wind speed rather than the ratio of energy (work) out to energy (work) in.

If you saw the old movie "Cheaper By the Dozen", you'll perhaps remember that to that "efficiency expert", efficiency was a measure of whether he could button his vest more quickly from the top down or the bottom up.

Jeez, I'm embarrassed sometimes, not to mention put off, by the one-up-man-ship of the nay sayers on this forum. Yes, millions of people speak your narrow brand of technical English, Gonzo, but there are billions of people on this earth. Can you read, and write, scientific Dutch? Or German? This is apparently a bright young student that you are putting down, and I have to say that the guy's English is overall better than yours and kerosene's. Not to mention that he and his cohorts are trying ro do something fundamental rather than surfing the web looking for something to nitpick. Sorry, but racing conventional sailboats ain't in the same league.

Cheers, High Tacker

 

What's your point? You are repeating what I said about the Law of Thermodynamics but pretending it is different. Also, Hollywood comedies are hardly a standard for scientific terminology. As for my English, what is your complaint? How do you know it is my first language?

 

that my friend is called tacking