Free(ish) Energy - part II - waterwheel

RiderOnTheStorm

not sure if this is a Physics thread, or Engineering, or plain old Science. Please move if its in wrong place.

I have had an idea for cheap (if not free) energy for sometime now, and dont have the means or knowledge to persue it. What do you think? Has it been done before?



From my secondary school physics classes, we were told that if you place a very narrow tube (open at both ends) in a bowl of water, that surface tension (and air pressure?) will make the water rise up the tube. What if the tube is shorter than the distance the water would usually rise? (ie section 'A' removed alltogether) Will the water flow out the top? Will the same surface-tension that made the water go up, hold it at the top?

In the diag below, I have put several tubes together but they would act indivudally. I think the same thing happens with bristles of a brush, or fabric (the close fibres / bristles act as a tube and raise the water). If the water could be encouraged to come down the outside of the bunch of tubes (and collected in cone 'B'), then it could easily power a waterwheel and make electricity. Can some energy be used power a pendulam to 'scoop' the water way? Could a siphon work if the water was raised to the top of the tubes?

your comments please . . . . .

Professor_Fink

RiderOnTheStorm wrote:

Will the same surface-tension that made the water go up, hold it at the top?

The short answer is yes.

You can make fountains of liquid helium, but you end up heating them up is you're using it to do work.

RiderOnTheStorm

drat, thought so....

how about if there is a syphon on top of the apparatus? once the water is raised to height of the tubes, can it be 'sucked' down by another tube? or a inverted funnel connected to a larger tube, covering all the tiny tubes?



or bending the tubes near the top?

Professor_Fink

I'm afraid that all of these setups have a static solution for water. It doesn't cause water to move, once it has reached an equilibrium position.

Capt'n Midnight

Sisal, hemp and cotton ropes will shrink when they get wet. With our climate you could imagine a very slow machine powered by the changes in length of rope according to our weather. The distances would be small but you would use levers.

IIRC they did something like this in Israel as a muscle analogue for expirements but I can't remember if they used salty water.

Professor_Fink

Thats not exactly an efficient means of generating energy!

Capt'n Midnight

If you can get money for old rope, why not energy !

RiderOnTheStorm

drat, I really thought that the siphon would work. I have used shoe-string siphons to water my plants while away on holidays......

back to the drawing board......

what did the guy who invented the drawing board go back to when the first prototype didnt work?

Professor_Fink

Basically the classical laws of physics are very well understood, and you won't be able to come up with a 'free energy' device based on those laws, because they all conserve energy.

The best you can do is an unusual energy source, like draining energy from the moons orbit.

Capt'n Midnight

Professor_Fink wrote:

The best you can do is an unusual energy source, like draining energy from the moons orbit.

That would not be a good thing. The moon has one face locked to us and is slowly drifting away. But it's also slowing down the earths rotation ( fossil cyanobacteria have shown there used to be over 400 days in a year !) and eventually the earth will slow down so much that the moon will be fixed over one part. So both planets will be locked with the same faces all the time.

Then the moon starts getting closer again, and if we are lucky it will break up when it hits the roche limit and make lovely rings

Professor_Fink

Eh, it'll take a long time for that to happen. Also, if you drain energy quickly the moon would smack into the earth, since the gravitational gradiant on the way in is pretty tame.

The Roche limit for the Earth-Moon case is 9500km... From the earth's centre! The Earth has a radius of ~6400km, so the limit is only 3000km away from the Earth, but the moon has a radius of 1700km, so now you have a roche limit where the surface of the moon is only 1300km from the Earth.

The Earth's atmosphere extends out to 800km (the exosphere). That's 500km between them. And energy must be being drained from the orbit already since the moon has gotten 380km closer to earth! That means no rings! Everything would hit the Earth.

So no lovely rings for us.

Gurgle

Capt'n Midnight wrote:

and eventually the earth will slow down so much that the moon will be fixed over one part. So both planets will be locked with the same faces all the time.

Let the green party of 1,500,000,000 AD worry about that one.
It'll keep the place running until we sort out zero-point energy.

Professor_Fink

Gurgle wrote:

It'll keep the place running until we sort out zero-point energy.

You do know you can't extract zero point energy, right?

Gurgle

Professor_Fink wrote:

You do know you can't extract zero point energy, right?

Not our problem, let them worry about it in a billion years

RiderOnTheStorm

i know there is no free energy, but my idea was to convert existing (unlimited?) energy into another source.

If atmos pressure raises the water up a narrow tube, then why cant a siphon pull it down again?

Capt'n Midnight

You could do that with Helium II , but not exactly practical seeing as how you have to put in so much cooling energy.

The water runs up by capilary action, until the forces on it balance.

If you had something like an oak tree, a real big one, it can pull may 50 gallons of water up a day. Transpiration gets rid of the water at the top. ( tree "sweat" if you like). Lets say you could tap into this to get a lift of 3m (haven't looked up to see the pressure a tree can exert - 10m is a complete vacuum and the water would boil off even if the tree could manage this)

so over 24 hours you generate 50gal x 4.55L/gal x 1Kg/L x 3m x 9.81m/s2 of energy = 6,695 Joules.


so taking into account winter when trees loose leaves and don't draw up much water you'd take 2 years to get 3,600,000 Joules of energy.

These guys will charge you nearly 15c including vat for the same amount of energy. http://esb.ie/main/energy_home/urban_charges.jsp