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speakeasy · 29-09-2009, 08:52

Quote:

Okay, but what's going to turn the flywheel? The energy has to come from somewhere.

Looks like the only initial option might be a weighted flywheel, first mentioned by Cheechako and seconded by geckosenator. DenverdOn, the masthead idea was just me ruminating on where the largest motion would occur on a sailboat. Needless to say, no one wants any appreciable weight added to the masthead. And the power to turn the wheel would come from boat motion. That's my query, how could we turn the considerable motion of the boat into electrical energy.

As for the flywheel idea, it seems like it could work. The second most movement on a boat would probably be in the forepeak, yes? A flywheel attached to a generator through gears to warp up the gen speed would certainly work there going to windward, but the whole rig would perhaps need to be adjustable to take advantage of different motion on a reach or run. I'm no mechanic but I might find one and put together something along those lines and tinker with it a bit.

Does anyone with mechanical/math skills have a rough idea how much juice could be drawn from such an arrangement and/or how feasible said installation might be for something like continuous charging?

LtBrett · 29-09-2009, 11:29

Already invented. Mount one of these on your mast head as a mast head light.
Mechanically powered flashlight - Wikipedia, the free encyclopedia
The linear motor could be scaled up so perhaps you could reliably light one led.

It would be an interesting study to see just how many watts can be generated by one of these linear motors while underway. While small, it literally is free power.

Brett

Cacique · 30-09-2009, 12:59

I have seen a small motorboat with a diaphram type bilge pump with the handle extended over the side attached to this was a weight and float so any wave motion causes the water to pump out.... could this be adapted to pump water through a generator?

Dick Pluta · 30-09-2009, 14:34

Just because someone hasn't done it doesn't mean it's not possible. Usually it's a question of practical or economical. I once designed and prototyped a device for one of the major car companies that used the pressure pulses generated when the tire hit bumps to maintain tire pressure. A simple little device mounted inside the wheel. Worked like a charm. It cost too much.

There are major development efforts right now to recover the energy in the shock absorbers of cars. It is claimed this system could produce all the electricity required by a car, including air conditioning. Sooner or later someone will figure out how to recover some of the huge amount of energy that comes out of the radiator and tailpipe. It's really a matter of economics. When it gets economically feasible, someone will do it.

As far as where the energy comes from and how much there is, here's the math. One horsepower is 550 foot pounds per second. That wave lifting my 22000 pound boat 1 foot in one second generates 22000 foot pounds per second or 40 HP. There's plenty of energy everywhere. The trick is capturing and storing it. Wave energy, tide energy, it's everywhere and people are collecting and using it. This ain't such a dumb idea.

Dick Pluta
AEGEA

pixitha · 02-10-2009, 08:30

Backpack

This is similar to what I think you want, something like this mounted higher up somewhere on the ship would pick up the back and forth motion of the ship easily.

barnakiel · 02-10-2009, 18:54

Had the same idea on many a downwind passage. Aside from the Seiko Kinetic - anybody seen a commercially available unit?

b.

Chief Engineer · 02-10-2009, 19:47

My DSSV---Via Admiral Sandecker and Patrick MacClanahan.

They are bringing together the Forces of NUMA and Madcap Magician

Quote:

Originally Posted by Chief Engineer

The Secrets are being kept underground at Groom Lake or HAWC....they are the Tesla Files that mysteriously disappeared after his death.....think the closing scene of "Raiders of the Lost Ark"

Quote:

Originally Posted by speakeasy

Intriguing! Can you elaborate, or are you being watched at the moment?

?

seandepagnier · 02-10-2009, 22:20

How about an electric motor and spring set to spin the motor when a rope is pulled. Hook it to your anchor or dock lines and generate electricity as the boat moves around with the waves.

Canibul · 03-10-2009, 03:33

I was thinkingl....a naked fat chick bouncing up and down on a small trampoline.....

no, of course it doesn't have anything to do with generating electricity.....yet.....

LakeSuperior · 03-10-2009, 05:28

Canibul...you will need a device that can capture many degrees of freedom...

Dick Pluta · 03-10-2009, 09:51

On a more serious note, there are a couple of real world issues. First, any such device would only work when the boat is experiencing some degree of "rolling" motion. It's unlikely you would get much on that perfect broad reach in calm seas. Like wind or solar, you can only collect it when it's there to collect.

Next, I think you would have to choose what kind of motion you want to harvest. My whole professional life was coming up with this kind of device and, although I haven't really given it a lot of thought, I think it would be a very complicated device that could function with both pitch and roll.

Finally, as far as an actual device, I can think of several ways to do this job. As always, the devil is in the details, but here are a some ideas for what it's worth.

First, a generator of any kind uses a coil passing through a magnetic field. That said, several device configurations come to mind. You could make a pendulum device that has a permanent magnet on the pendulum passing through a fixed coil. The pendulum would swing with the motion of the boat, either pitch or roll, generating a pulse of electricity as it passes through the coil. Kind of like your inclinometer.

Another possibility would be a device like a gas spring similar to those used to hold car hoods open. Picture a cylinder containing a piston with one end open and the other sealed. Just a piston, no piston rod. The piston would be a permanent magnet and a coil would be wrapped around the cylinder. The "open" end would be connected to the sea below the boat. As the boat moves up and down, water pressure on the piston would move up into the cylinder, passing through the coil and generating an electrical pulse and compressing the air in the closed end of the cylinder. When the wave passes and the water pressure decreases, the air pressure would push the piston back, generating another pulse and resetting the device for the next cycle.

Any such device using the motion of the boat would produce power intermittently, so you would have to charge a battery to make usable power. That means that you would have to reach charging voltage with the device and put small bursts of energy into the battery. Since it would be at work all the time, you might be able to accumulate enough power in the battery to run whatever device it is you want to run. You might be able, for example, to charge a capacitor and discharge it into the battery when the charge reached an adequate level.

It would be a simple matter to make a proof of concept model but, as I said earlier, the devil is in the details. How big would the coil have to be to generate a reasonable amount of power? For the cylinder device, you would have to move a lot of water quickly, so a big hole in the bottom might be required. Who knows, the infernal machine might be as big as a house. The world is full of good ideas. The really hard part is turning concept into workable reality.

Dick Pluta
AEGEA

Therapy · 03-10-2009, 10:05

Quote:

Originally Posted by Dick Pluta

The really hard part is turning concept into workable reality.

Dick Pluta
AEGEA

That back pack didn't move much and the runner got 44 watts. Pretty cool.

Canibul · 03-10-2009, 11:46

I don't see why the pendulum device would have to be dedicated to either pitch or roll motion. If it were mounted on a freely rotating horizontal plate that was weighted on one side, wouldnt the free swiveling pendulum base make it responsive to both pitch and roll? In addition, the motion of the weighted base plate could be added to a vertical shaft that the pendulum was driving as it also swung toward the constantly changing low spot.

How about a vertical shaft with a series of horizontal weighted plates free to rotate as the shaft moves in pitch and roll? If you made the plates different diameters, you could, in effect, harness more of the kinetic energy due to different rotational speeds.

If they were fitted with simple ratchets where they are attached to the vertical shaft, they could all drive in the same direction. The entire assembly could be sealed in a vertical PVC tube to be waterproof.