# Making ancient time water wheel to lift water

1. Nov 27, 2014

### shaks

I have one project of developing setup to lift heavy water at some height. A setup that take less energy as compare to traditional water pumps. I was searching on net and I found giant "water wheels" of ancient times to lift water.

Like this one http://en.wikipedia.org/wiki/Norias_of_Hama

Is this possible to rotate this with electric motor and make setup to lift water which is efficient than traditional water pumps?

I was thinking that due to circular motion, inertia, momentum, centripetal force, etc might be this can be more efficient than traditional water pumps!. I thought it may require more power to move it from rest but once wheel gets momentum then it requires less power as compare to moving from rest.

For example:
Wheel diameter: 30 meter
Water mass: 100,000 kg per round
Speed: 1 round in 10 minutes
Driven by: electric motor

I don't have any physics background so please excuse me if you feel this is stupid idea. http://www.thescienceforum.com/images/smilies/icon_rolleyes.gif [Broken]

Shaks

Last edited by a moderator: May 7, 2017
2. Nov 27, 2014

### Danger

I'm not sure about that. While I don't know any math, my intuition thinks that the large diameter would also make for an awful lot of leverage on the loaded side to overcome.

3. Nov 28, 2014

### shaks

Wheel diameter: 30 meter
Water mass: 100,000 kg
Speed: 1 round in 10 minutes
Driven by: electric motor

100,000 kg water = 26,417 gallon per round (1 gallon = 3.78541 liter/kg)
26,417 gallon / 10 minutes = 2,641 gallon per minute (gpm)

I found formula of calculating pump power according to gpm.
Motor HP = (height in feet * gpm) / 3960
Motor HP = (98.42 x 2641) / 3960 = 65.64 HP = 48.95 KW

So if traditional pumps are used to lift 2,641 gpm then estimated 48.95 KW motor is required.

Any idea if same amount of water is lifted by water wheel then how much electricity will be required?

I believe that moving wheel from rest to required speed will take same electricity but once wheel get momentum then it should take less electricity to keep that momentum/speed?

Shaks

4. Nov 28, 2014

### Bystander

Only if you leave the water on the wheel, which defeats the purpose.

5. Nov 28, 2014

### shaks

Explain with some logic, why its not possible?

Shaks

6. Nov 28, 2014

### Bystander

The momentum of the water on the wheel is lost at the top, and you are constantly having to "replace" it.

7. Nov 28, 2014

### shaks

8. Nov 28, 2014

### A.T.

That is the modern version of such devices:
http://en.wikipedia.org/wiki/Hydraulic_ram

I doubt it. The whole point of these wheels was to use the energy of the flowing river. But if you want to use electric energy, the current electric pumps are already the result of decades of optimization for this purpose.

PS: I think you don't really mean "heavy water", do you?

Last edited: Nov 28, 2014
9. Nov 28, 2014

### shaks

You pointed a good thing. :)

The point where I am seeing a difference between traditional pumps and water wheel idea is the following:

1. Traditional pumps are immediately stopped when power is switched off but wheel is in circular motion so even electricity is switched off then still wheel will be in circulation for a few seconds due to its momentum until air, water and other frictions don't overcome.

2. Due to circular motion "centripetal force" helps against gravity, is this true?

Heavy water = big amount of water :)

Shaks

10. Nov 28, 2014

### jbriggs444

1. Any effect that you get from residual motion as the wheel slows down after power is turned off is "paid for" by extra effort that was required to get the wheel moving when the system was started up. There is no free lunch.

2. Again there is no free lunch. Energy is conserved. There is no point in looking at complicated machines and hand-waved explanations to find the place where this manifests. Any extra lift that comes from "centripetal force" or any other effect will have been paid for by extra effort somewhere and somehow.

If the water moves from bottom dead center to top dead center and is acted upon by "centripetal force", that centripetal force will have worked to oppose gravity for the first half of the movement and to assist gravity for the second half. That's how it balances out for that particular scenario.

11. Nov 28, 2014

### Staff: Mentor

You have it backwards. An old style water wheel does not utilize centrifugal force, but a new style pump does.

12. Nov 29, 2014

### shaks

A.T., you gave good idea of Hydraulic ram pump and running wheel with "flowing water/river" and I am thinking to use both as combination.

The first priority is to "rotate water wheel" with "flowing water". Now the question is how much water required to rotate such wheel? I mean following:

1. How much water flow required
2. Above water flow can rotate how big wheel
3. How much water can be lifted in one round

I think this is good idea, I created one diagram of my idea regarding flowing water.

Will this work i.e. we can create slob to create pressure in water flow so wheel may be rotated but the question is how to measure force of flowing water?

How to measure force of flowing water or kinetic energy or potential energy of flowing water?

Any idea on this?

Shaks

13. Nov 29, 2014

### Staff: Mentor

The pressure is expressed in the height it fell. The energy is pressure times flow rate. So what exactly are the requirements?

I really don't think you are recognizing just how difficult and expensive it will be to build a 30m water wheel.

14. Nov 29, 2014

### jbriggs444

Looking at the diagram, it seems that your scheme is to use water-powered water wheels. The first wheel uses a 1 meter downward slope to power a wheel that lifts water by 30 meters (net 29 meters). Energy conservation requires that the fraction of water lifted by this wheel can be no more than 1/30 of the total flow.

The next wheel uses another 1 meter downward slope to lift the water by 31 meters (net 29 meters after the two drops) Energy conservation requires that the fraction of water lifted by this wheel can be no more than 1/31 of its input flow.

If you wanted to get (let's say) 99% of the water to be lifted by 29 meters you would need to allow 1% of the water to fall through a total of about 2900 water wheels ending with one that is roughly 2.9 kilometers in diameter.

Then you'd still need to somehow get enough water to the top of your 2.9 kilometer mountain (or up out of the bottom of your 2.9 kilometer deep wheel well) to make up for that 1% leak rate. The efficiency losses in such a scheme would be enormous.

15. Nov 29, 2014

### Staff: Mentor

Oh, requirements were in the first post: at 50% efficiency, that's about 90 kW. Its a pretty high flow rate and lift.

16. Nov 29, 2014

### shaks

You mean that one wheel can lift around 1% of total water flowed under the wheel? Can you copy formula here?

I am looking to measure the force of flowing water in these mini canals. For example if canal is 5' wide (or wheel width +1 feet extra) and 5' depth and 10-20' long. We can measure how big wheel this water can rotate if we can measure the force of flowing water.

Shaks

17. Nov 29, 2014

### shaks

18. Nov 29, 2014

### voko

Your question is not answerable in this forum. You are not posing a problem in physics; you are posing a problem in engineering and economy. We can discuss the principles water wheels and pumps; we could even figure out estimates of their efficiency. But a "minimum cost" design is a totally different beast. For example, from a "minimum cost" standpoint your idea that "these wheels will cost one time" is false. They will have wear and tear; they will need maintenance. It is one thing to maintain a compact device, even high tech, and quite another to maintain a huge structure.

From the engineering/economic point of view, your question is invalid to begin with. Before you literally go inventing a wheel, you should get a firm grasp of the contemporary technology used to lift water and what costs its use incurs. Knowing the cost structure, you can pose valid questions: how can I optimize the costs? Where could I save most?

19. Nov 29, 2014

### sophiecentaur

If your initial source of energy is from moving water then there is an attraction in avoiding the inefficiency of transforming it to Electrical and then back to Mechanical again. A large,slow water wheel could be used to drive a 'conventional' pump using gears of a belt to produce a faster rotating small pump directly. But, as voice says, the whole project would need to be costed - for both Money and Water flow. If there is plenty of water available to produce your motive force then it's FREE!, which could be highly relevant.

One way to look at the feasibility would be to decide how much water flow you need from your pump and what height it needs to be lifted. That will give the required Power (=mass per second times g times h). Then you need to estimate the amount of available Hydro power you have - (Available water mass per second times g times drop). You would be lucky to get as much as 10% efficiency out of an overall system without some cleverness, I'd bet so you can check whether your available Power In is ten times the wanted Power Out. If not, then think again.

20. Nov 29, 2014

### Danger

One thing that you might investigate is attaching an auger (Archimedes Screw) directly to your paddle wheel. It still won't be very efficient, but at least it would remove the need to translate the energy from rotational through other forms.
I suppose that construction costs could be minimized if you sneak into an amusement park at night and steal their Ferris Wheel...

21. Nov 29, 2014

### sophiecentaur

That could be a possible solution. But, as in all Engineering projects, it's the actual numbers that count. We need to know more of the actual application so as to have an idea of the Budget (Financial and resource) involved.

22. Nov 29, 2014

### sophiecentaur

@shaks
There is a universal principle that says you cannot get out more than you put in; I think you are aware of this because you realise we can't contemplate perpetual motion here but I am not sure you are really applying that principle rigorously in your thinking.
There is another practical principle that tells you that most jobs are done, these days, by nearly the most efficient method available; talented Engineers have worked on these things for centuries. Pumps have been developed to work over a huge range of flow rates and heights and, unless you can come up with something truly revolutionary, you are unlikely to make any huge improvement. That's not just an ultra-conservative statement,btw, and there is always room for advances. An example of a massive advance in Hydraulic Power systems was when they shifted from the Paddlewheel for boat propulsion to the Screw Propellor - which actually dealt very well with the problem of energy wasted in the water flow.
Anything that involves water flowing round circuits is inefficient because
1. you get turbulence and
2. The water emerging from the 'other end' always needs to be shifted out of the way, which means it must be moving and carrying away Kinetic Energy. Adding another component into your energy chain which involved flowing water is bound to introduce losses so it is best avoided.

23. Dec 1, 2014

### shaks

Thank you everyone for helping regarding my project.

I have done some more research that's why there was break in replying to this thread. Now I am thinking on different angle and all depends on one assumption that I am going to ask in this thread. Then I will update here some more details of project so you people may have more idea what I want to do.

1. One 5-10 feet wide canal with at least 2-3 feet deep water coming non-stop
2. Canal length = 400 feet
3. Canal slope = 30 feet. It means from one side canal is 30 feet higher than ground and on second side canal is at ground. It might be like a falling bridge.

So above is great slope and water is coming regularly without stop with full pressure.

1. Wheel and canal width is like this video
I mean canal width is according to wheel so there is no extra water flowing just for nothing. Water flowing is creating force.

2. Another example of wheels is a row here at wider canal but wheels are rotating fast and lifting good amount of water. specially you can see at around 1:00 that water slope or flow is not huge just with normal water flow, 3 wheels in a row are moving. I can assume more water flow than this in my canal.

Another example here about water flow and how much wheels are dipped

So what you people think that if wheel and canal width is according to each other i.e. water is not flowing extra from right/left and there is 20-30 feet slope from start to end of 400 feet canal and there are 20 wheels of 20 feet diameter in a row, can each wheel lift 2%-3% of flow water?

There might be around 100,000 gpm water flow in a canal coming from 30 (or 20 feet if 20 feet is fine) feet height. 100,000 gpm is big flow and this water should rotate wheels very fast.

Since I want to lift water at 200-250 feet height so this is not possible to make wheels of 200-250 diameter just to lift 2-3% of flowing water (although earlier I was thinking to make each wheel of 200-250 diameter). Because if each wheel is 200-250 diameter wheel then for just 5 wheels I need 1100 feet canal that's very hard to manage and big wheels to manage.

Now I am thinking of around 20-30 feet diameter wheels which can move piston like this wheel and then that piston can lift water at 200-250 height. So wheels height and paddles are created in such way that water force can move piston which can lift maximum weight.

So in short do you think that 1 wheel can lift 2%-3% of flowing water?

I will update more here about my project and what I am thinking but first I need opinion on above question.

Shaks

24. Dec 1, 2014

### mmeftahpour

I have a question. they make it in circle form, because there is no need for external energy. (just energy of river)
if you want to use electrical motor why you use the wheel?