Reverse Wind Generator

[senormechanico]

True story:

I once had an employee who thought he knew more than anybody about just about everything.
He drove a van which he had jacked up in the back suspension.

He did it to "get better gas mileage because it [was] always going downhill".

[Therapy]

Originally Posted by slomotion

I always thought the term "wind generator" was kind of odd. I mean it sort of suggests a device that produces wind - so maybe you're on to something. OTOH, I tried reversing my diesel generator and it didn't produce any diesel at all.

Hmmm ...... time for another beer.

Funniest post in weeks!!

[Sailmonkey]

Originally Posted by geckosenator

wow

I am surprised so many people find this concept laughable.

Really????

Originally Posted by geckosenator

To the people who think it is like a towtruck lifting itself or defies conservation of energy, you need to go learn physics you are wrong.

Are you telling me I wasted my time and money studying marine engineering?

Originally Posted by geckosenator

The fact is, boats with an air fan to power them do exist, and it is a working concept. I don't think you could go very fast, but that is ok, I don't like motorized boats that go more than 1-2 knots (might as well be sailing)

In south Louisiana they call them airboats.....usually are powered by an aircraft engine or a chevy 350. Not only not efficent, but not all that powerful when compared to other methods.

Originally Posted by geckosenator

Many sailboats (mine included) already have a wind generator capable of about 1hp. This may not be a very efficient way to propel, but I have no other means of propulsion besides rowing, sculling or sailing. It would be a means of backup propulsion and would give great manuverability in tight areas since the wind generator can aim in any direction.

Although most sailboats tend to resist sideways motion

Originally Posted by geckosenator

All it requires is bypassing the control circuitry (brushed alternators) to cause the generator to be powered from the battery. It might help to have a dc-dc converter so you can pump more amps in it, and have speed control.

[David M]

This has been tried numerous times and it works at propelling the boat. Its just not as efficient as having sails.

When you think about it, a sail is a much larger blade. Energy is converted to mechanical energy in proportion to the kinetic energy, 1/2mv squared, of the air that has changed direction. Sails deflect more air and that energy is applied directly to the boat.

[pressuredrop]

gecko - i think there is some confusion here, are you talking about using the wind gen like an airboat?, or focusing it on the sail so your always sailing ddw?

i dont think theres much hope for the former, the latter might get you going 2 knots

[Sailmonkey]

If he's talking about steering the thrust from the wind gen, he means to use it like an airboat.
While not quite like a towtruck trying to pick it's self up, it could be better compared to pushing the QEII with a british seagull.........

[seandepagnier]

I want to use it for propulsion. Yes it would not be powerful, but I do not like boats with powerful motors. I laugh at people who are impatient and use gas motors. I also get pissed when I see people motoring when there is more than 3 knots of wind (watch out I'm getting torpedos) Dont want to hear them or smell their fumes.

Currently I have a canoe paddle to power myself when there is no wind. I suspect the wind generator would provide comparable thrust which would relieve me of rowing. This would give manoeuvrability in tight areas and the ability to move the boat slowly without a trolling motor. If I can work out the electronics, I believe it is just a switch to bypass the control circuit board (disconnect it) and apply power directly the the alternator.


A lot of my ideas so far that I have posted (like repairing sails without sewing, packing my displacement boat with styrofoam to make it unsinkable etc...) got some funny responses and only a few people even considered them possible. I have done all of them (and a lot more weirder things) with success and I think I can again with this too. The main reason people might try this is, they already have a wind generator, so the cost is $0 and it gives another means of propulsion.

Unfortunately I seem to be much faster at thinking up stuff than implementing it, I'll post and update when I get it working ;-P

I did not think about aiming the wind generator at the sail, I don't think this would have a very useful effect but maybe there is something to it that I have not realized. I like it when people think of stuff like this that I overlooked.

The fastest human powered boat used an air propeller. It had the driver pedal to make it spin, and the boat achieved speeds of 18 knots on hydrofoils. It can be very efficient, but the blades probably need variable pitch to get good efficiency at all speeds.

Am I wrong to think that in theory it is more efficient to use a air propeller than water propeller if the wind is dead and you are traveling against the current? This would be assuming ideal propellers and maximum efficiency.

[marc2012]

Now know why so little progress motoring into the wind.Motor pushing forward gen pushing back,Quoting earlier post "hmm time for another beer"marc

[onremlop]

Originally Posted by cal40john

I think you need a wind generator closer to this size





From:
Windmill Sailboat: Sailing Against the Wind : TreeHugger

John

I don't think you want to go to the front of the boat on a windy day. This would be worse than getting hit in the head by the boom.

[Sailmonkey]

you're forgetting that air is less dense than water, so you'll sacrifice some due to slip. A wind generator will not withstand being motorized for long, the smoke will come out of the wires.

[denverd0n]

Originally Posted by pressuredrop

gecko - i think there is some confusion here, are you talking about using the wind gen like an airboat?, or focusing it on the sail so your always sailing ddw?

i dont think theres much hope for the former, the latter might get you going 2 knots

You've got it exactly backwards. Using the propeller to move the boat like an airboat would work. It would work very badly, and very inefficiently, and probably wouldn't even get you moving a half a knot, but it would work. Aiming the propeller at the sail to try to generate wind to move the boat, however, is an attempt to violate the first and second laws of thermodynamics.

[senormechanico]

I'd like to see a Youtube video when you hook it all up, especially the first few seconds when you throw the switch.

[seandepagnier]

Originally Posted by senormechanico

I'd like to see a Youtube video when you hook it all up, especially the first few seconds when you throw the switch.

I bet you are hoping I smoke it


Half a knot is fine. The wind generator is not going to smoke if I do not give it more power than it can handle.

Air propellers are just as efficient as water propellers,

[Pau Hana Daz]

i think there is some confusion here, are you talking about using the wind gen like an airboat?, or focusing it on the sail so your always sailing ddw?

i dont think theres much hope for the former, the latter might get you going 2 knots

I think it would be far more effective to just couple a generator to Sir Isaac's feet as I'm sure he's turning some serious underground RPMS about now...

[Therapy]

geckosenator,

My guess is that you really are a politician.