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Heating Water Through Friction

02/12/2008 10:36 PM

Hello to all you brilliant enginerring minds out there!

Hi, my name is Melanie and I'm a 15 year old scientist-to-be. I have a bit of a problem that I've been trying to solve, and I'm not quite sure if its plausible, but it is very interesting nonetheless.

What I want to do is heat water to 65-70 degrees through friction. This is basically the main layout of my machine so far : I have two cans, one inside the other, and it is going to spin using the power of a metre long elastic band chain, on an axle. The elastic will be hooked to the ground or some other object (e.g. a tree), and the axle with the cans will be on some sort of easily built stand.

Does this idea sound plausible (heating water to an average of 70 degrees through friction) and are there any alternatives?

Ideas I've had so far include:

- Insulating the outside can (prevent heat loss)
- Adding in pebbles to increase friction

Is there anything else?

I have additional questions as well...

-On an axle rotated by an elastic band, is it more effective to have the band level with the axle or on a differnt level?

-Imagine the axle is being rotated in the centre by the rubber band. There are two cans on either side of it, being spun. If I was to enlarge the diameter of the part of the axle being rotated by the elastic, what would the benefits be?

-How can I make this design more efficient?

One of my goals with this project is to make it out of recycled and supercheap materials (e.g. old wooden sticks, elastics, old coffee cans), so please keep that in mind :)

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#1

Re: Heating Water Through Friction

02/12/2008 11:51 PM

Hi Melanie - It will work but. . . . Other will explain.

You deserve some credits at school.

A slight improvement may be to replace the pebbles with vanes,

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#2
In reply to #1

Re: Heating Water Through Friction

02/13/2008 12:21 AM

Thanks :) I'm wondering how the vanes will work, perhaps I should have clarified my design further: The outside can will be adhesed to the axle, the inside can, containing the water, will be freely moving around inside the other. I'm not quite sure about the physics behind this... I'll definetly have to look into that.

I'm wondering if I should narrow this down first, and try to find a way to maximize the friction effect inside the cans before going onto designing the whole system.

Using logic I can assume that the friction causing heat will come mostly from the cans being heated, as opposed to the water. So my theoretical goal right now is to find a way to hit the can alot without damaging it and in the right places, while retaining heat inside the whole can system.

I have a lot of work ahead of me :(

thank you for all your help, maybe this new set of questions will again strike your interest and help me learn a little more

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#3

Re: Heating Water Through Friction

02/13/2008 2:29 AM

Hello Melanie,

Your post is very interesting, because it is new idea .

But I think that, it is not effective project in now. You can use winds energy to do that e.g. Wind energy → electric energy → to heat water.

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#4
In reply to #3

Re: Heating Water Through Friction

02/13/2008 3:01 AM

Hi

To make energy by wind is an old way which everybody knows.

The ideas we are discussing seems to be new and interesting. it may be not effective

as you yourself are thinking, but having a trial is a good way for Melanie. the result will be evaluated after Melanie finishes his work.

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#8
In reply to #3

Re: Heating Water Through Friction

02/13/2008 11:02 AM

Yes but wind energy is a very expensive commodity; despite the increased efficiency, it wouldn't be economic enough for third-world countries.

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#5

Re: Heating Water Through Friction

02/13/2008 5:35 AM

<...heat water to 65-70 degrees through friction...>

The enthalpy of water at 70degC is 293.0kJ/kg (from steam tables).

Assuming it starts at 15degC, the enthalpy is 62.9kJ/kg (from steam tables).

So the difference is 230.1kJ/kg; that is the amount of work to be put in from the drive mechanism to heat the water only.

Knowing the mass of the water inside the can will determine, for a first approximation, the amount of stored energy to be released from the elastic band mechanism. However, sliding rubber-over-rubber during the energy release is a high-friction event, and it might be that the losses from the band mechanism are very significant in comparison with the energy that is transferred to the can and dissipated as heat within it; experimentation is required in order to evaluate this effect.

<...Insulating the outside can (prevent heat loss)...>

As heat is dissipated inside the can, its surface temperature will rise. Assuming no input is required from the sun for this device (or perhaps that the tree is shading the equipment!) some insulation will be of value in slowing the release of a portion of the energy dissipated in the can as lost heat, as the water temperature rises above ambient.

<...Adding in pebbles to increase friction...>

Anything that increases turbulence within the can will add to the torque presented to the agitator; another way might be to add some baffle strips to the inner surface of the outer can and the outer surface of the inner one, for example. If rotation speed is maintained at this greater torque, then the rate of energy dissipation inside the can will rise, which means that for a faster energy input, there will be a faster rise in temperature.

<...Is there anything else?...>

As an alternative energy source for comparison purposes for an effective water heating device, consider painting the outside of the can black, placing it inside a glass outer container with a lid, and using an array of mirrors to direct sunlight onto the can. Compare the effectiveness of this method of heating the water with the elastic band drive.

<...Is there anything else?...>

Please report back on CR4 with the outcome of these experiments, as it will be of interest to many readers.

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#12
In reply to #5

Re: Heating Water Through Friction

02/13/2008 11:04 PM

The usual way to work out the energy required (for liquid water)

E = M C dT

M = Mass, C= Specific heat of water 4.19kJ/kgC, dT= change in temperature

Using your numbers gives

E/kg = 4.19kJ/kgC * (70-15)C = 230.5kJ/kg

Same answer, hopefully clearer to a student.

ffeJ

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#21
In reply to #12

Re: Heating Water Through Friction

02/14/2008 4:43 AM

Agreed.

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#35
In reply to #5

Re: Heating Water Through Friction

02/14/2008 1:51 PM

its is acceptable for only to some extent.

but however frictional loss itself has to be protcted

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#6

Re: Heating Water Through Friction

02/13/2008 7:40 AM

Hi,

It can be done. Use Hen's idea of vanes if you can adapt that to your project. You might try Googling Joule's Mechanical Equivalent of Heat experiment.

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#7
In reply to #6

Re: Heating Water Through Friction

02/13/2008 7:52 AM

Bingo! Here it is, for convenience of the original poster: http://en.wikipedia.org/wiki/Mechanical_equivalent_of_heat

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#9

UPDATE

02/13/2008 11:19 AM

Thanks a lot for all your suggestions, I will definetly try these out.

My partner for the project and I are now working on designing the experiments, we are going to be using an electric kettle as the basis for comparison.

We also might combine the ideas of solar heating with mechanical heating through friction. The main goal of this is pasteurizing the water (I may have left this out previously) so UV rays during solar pasteurization will react with the oxygen in the water and kill some of the bacteria before letting friction do the heating work (as the problem with solar heating is it will take a minimum of 6 hours on a sunny day to pasteurize!)

This project is still in the developing stages, so stay tuned for updates within the next 2-3 weeks, by which time the entire project should be finished. We haven't yet built a prototype but are working on sketching out and planning design ideas.

What we still need to do is:

  • Maxmize friction within the cans (heat will be transferred from the friction between the cans to the water as opposed to directly from one can to the water; this is because water will not heat up through direct friction unless wicked amounts of energy are applied)
  • Minimize friction between axle and base (we may consider using ball bearings, however these could be expensive and defeat the purpose of using recylced materials)
  • Maximize energy expelled by elastic band as well as speed and length of time for turning of the axle
  • Use as few materials as possible; make it very economically viable for third world situations
  • Also, we need to work out how to do the solar heating step in an efficient manner

New suggestions are welcome thanks again

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#18
In reply to #9

Re: UPDATE

02/14/2008 2:33 AM
  • Maxmize friction within the cans (heat will be transferred from the friction between the cans to the water as opposed to directly from one can to the water; this is because water will not heat up through direct friction unless wicked amounts of energy are applied)

Wicked amounts not required. Interestingly, and as others have mentioned, you are in effect repeating Joule's original experiment -- and of course he's the guy for whom Joules are named. The experiment formed the foundation for one of the key principals of physics. So whatever work you put into the water will result in an equal amount of energy in the form of heat.

If you search through this site on windmills and water, etc. You should be able to find a recent discussion re a windmill being used to heat water to 150 degrees or so (for domestic hot water). The friction is intermolecular (from stirring and turbulence) more so than the friction against the side of the cans where the flow is potentially laminar (meaning stuck to the surface and not moving relative to it).

Great project! Very impressive.

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#10

Re: Heating Water Through Friction

02/13/2008 2:21 PM

I was out in the country today.

If I understand correctly you want to use the friction between the 2 cans for the source of heat.

Incidentally I saw a relevant accident today. The bearings on the back wheel of an old ldv was damaged or gone. The wheel was turning on the stub shaft. when the wheel came off the shaft was sizzling hot.

The accident happened 200m in front of me as I was accelerating to pass the ldv. The friction between the disk and the pads on my car (ABS) also caused a lot of heat and I am sure I have lost a few mm somewhere.

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#14
In reply to #10

Re: Heating Water Through Friction

02/13/2008 11:42 PM

Thats very interesting and I'm sure this theory can be applied to the cans... I'm wondering if it would work better with two cans that are closer in size, as opposed to two cans with very differnt diameters?

I think I'm going off on tangents here... but it might be a good idea to write out what Im thinking now...

From what I can remember the equation for finding the force of friction is this:

Ff = coefficient of friction x weight
This means:

  • Increase weight of water inside can (could that translate into increasing the size and therefore water capacity of the can?)
  • Insert materials on the inside with a high coefficient of friction.

Are there any more relevant equations you can think of that would make sense, too?

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#30
In reply to #14

Re: Heating Water Through Friction

02/14/2008 10:49 AM

Close in size is good - you want sufficient viscous drag so that the work done on the water is greater than the losses. But it will be hard to tolerance using just a pair of cans - perhaps you should use several cans with their sizes alternating between erect and inverted cans (the sizes should be spaced as closely as practical while avoiding contact.

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#151
In reply to #30

Re: Heating Water Through Friction

01/10/2011 7:41 PM

what about a tesla turbine, it rotates at very high rpm's you might see some temp. increase

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#11

Re: Heating Water Through Friction

02/13/2008 10:56 PM

Just a quick concern, with enough friction to heat any volume of water you will need to account for wear on the cans. Reducing this wear will lower your heat.

How about making the contact out of a rough fabric sleeve that can be replaced at need?

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#13
In reply to #11

Re: Heating Water Through Friction

02/13/2008 11:31 PM

Hmm, that's a good idea, but we'd need to find a material with a low heat capacity to act as a heat transferring device... what we want is to have something that heats quickly and loses heat quickly (e.g. rocks and metals). I'm afraid that wrapping the inside can, containing the water, will insulate it further.. water has a high heat capacity and I think that insulating it further will make it heat even slower... I'm not sure though. Please tell me if this is wrong.

What would be a good material? I think cotton would work horribly, I know from experience at sailing and at camp that it steals body heat (I'm assuming it retains it). If this is not so then cotton would work well, if it gathers heat and then transfers it.

Thanks a bunch for your reply :)

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#15
In reply to #13

Re: Heating Water Through Friction

02/13/2008 11:49 PM

I would look to copper as a potential conductor of heat friction.

how about a ceramic tile but try to retain heat not evaporate it.

spun as the armatures of a powersource, perhaps a bit of a shock, might result: might be fun, then again might not.

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#16
In reply to #15

Re: Heating Water Through Friction

02/13/2008 11:52 PM

How expensive and available is copper?

Other than the economic issues regarding it, it seems like a very good idea as I hear copper is an excellent conductor of heat.

I'll investigate it, thanks.

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#19
In reply to #16

Re: Heating Water Through Friction

02/14/2008 3:00 AM

scrap wire is easy to locate. some work required. Almost every thing electrical has copper wire.

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#24
In reply to #13

Re: Heating Water Through Friction

02/14/2008 8:52 AM

I can't let you keep going on like this it is killing me. What you want is a new tech. already being put into use. It is a water slammer. Essentially it is a solid round with holes drilled to certain depths depending on the appl. also the amount of holes also differs for the appl. meaning the temp. can be controlled according to the amount of holes in the cyyclonic cylinder being used. Also the speed I have observed is a constant 3750 rpm Hope this helps you further.

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#31
In reply to #13

Re: Heating Water Through Friction

02/14/2008 11:12 AM

Hi Melanie,

How do you propose to turn the axle -> cans? Are you using a hand crank assembly or some other method?

-John

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#39
In reply to #31

Re: Heating Water Through Friction

02/14/2008 4:38 PM

A hand crank would be simple... I don't think my partner and I are too worried about this at the moment though. Why, what do you have in mind?

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#80
In reply to #39

Re: Heating Water Through Friction

02/17/2008 9:38 PM

Dear Melanie, I applaud your conviction to your project. If I might suggest a simpler method: back in my post #17 I suggested that you check out SPR Cavitation on You Tube. It shows a rotating drum with holes bored in it in a close fitting sleeve spun at roughly 1500 RPM. This "pump" generates hot water or steam depending on the number of holes.

What drives the cylinder, I believe, is immaterial. But please check out the site. It may give you and your partner ideas.

Regards Dragon

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#81
In reply to #80

Re: Heating Water Through Friction

02/17/2008 9:50 PM

Oh I definetly took a look at it, very interesting! sorry I couldn't get back to you, with the 60+ posts there is so much to read!

Yes, we were a little inspired and considered doing a series of cans with holes in them... we still are in the midst of developing the design to be prototyped so this design idea may come into effect... We'll just have to see

Thanks!

Melanie (& Duncan)

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#82
In reply to #80

Re: Heating Water Through Friction

02/18/2008 1:54 AM

Interesting. One of the sites that pops up is this. Towards the end it contains the words that many people on CR4 love (not) so much - " Over Unity ".

Melanie, welcome to the twilight zone !

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#83
In reply to #82

Re: Heating Water Through Friction

02/18/2008 10:56 AM

The twilight zone, huh? Hehehe, from what I've heard over unity is an impossibility!

The world of engineers is very strange, and very funny, I like the intelligent humour that is floating around the discussion. I'm definetly looking forward to doing this professionally in the future (that is, if I don't go into biomedical illustration)...

Getting a little more off-topic...

As an engineer (this is for everyone out there) what is your view on biology; how much does it interest you?

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#84
In reply to #83

Re: Heating Water Through Friction

02/18/2008 12:24 PM

You're quite right about over unity machines -they pop up with regularity on CR4 and usually produces howls of indignation/laughter/ridicule. I was surprised to find it tagged on to the given link, but it made for a good laugh.

Views on biology.....that's a pretty open/big question. Like most people on CR4, I take an interest in all things related to Science and Engineering. Anybody with an inquiring mind can hardly escape biology related topics. Most disciplines overlap. I'm not sure what sparks my interest in any given thread, but almost any thread found on CR4 can produce good discussion. The humour found throughout is brilliant, and is in no small part due to the diversity of members. Well done on starting such an interesting question Melanie, I'll look forward to reading further posts.

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#88
In reply to #83

Re: Heating Water Through Friction

02/18/2008 12:51 PM

Melanie; Extremely! I'm an environmental scientist by profession (Environmental, Health, & Safety Coordinator), with a major in environmental biology, chemistry minor. I've worked a lot with engineers over the years, but am not one. Biomed illustration didn't even exist as a separate career field not too many years ago, so I guess you are more 'cutting edge' than you may be aware of...

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#96
In reply to #83

Re: Heating Water Through Friction

02/19/2008 10:37 AM

As a biological animal, we should be interested in the topic.
Having said that, biology as 'studied' varies from the rigorously checked to the uncheckable, so you need to be careful with whom you work. My strong prejudice, reinforced by more years of observation than I care to admit, is that people working in any of the sciences do well to have a first degree in Physics or Physical Chemistry, and that from an A* rated university in the field. The sole exception to this is perhaps in Physics itself, where it is good if the mix includes a higher proportion of people with first degrees in mathematics.

Fyz

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#87
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Re: Heating Water Through Friction

02/18/2008 12:49 PM

Arrrrgh!!!

I looked into this last night, and I am tempted to call the people promoting the concept today (they are just about an hour from here). I note that Griggs, the inventor, is no longer with the company, and he seems to be the one who made the over unity claims. I have some contacts at Georgia Tech, so I may see if the prof from there is rumored to have witnessed an over-unity demonstration actually did.

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#93
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Re: Heating Water Through Friction

02/19/2008 1:59 AM

The video clip was running so nice, then all of a sudden they drop that in. It's like watching Gone with the Wind, only to finally hear Rett say "Let's give it another shot", and Scarlett exclaim "Screw the farm".

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#98
In reply to #93

Re: Heating Water Through Friction

02/19/2008 12:46 PM

LOL!

It seems that hardly a day goes by when I don't follow up some lead, only to find my jaw dropping at the "denouement".

I recently pondered how on earth the Tesla (car, not nutcase) people came up with their 135 mpg equivalent, having calculated it at about 50 mpg (using a well-to-wheels approach, assuming, as the DofEnergy here does, that across the US electricity is generated with 32.8% efficiency). The Tesla website references a section of law, which was created for our CAFE (corporate average fuel economy) standards. (Pursuant to these, manufacturers which have an average fuel economy worse than the standard are fined.)

Well, the DofE calculations start off just fine, and using them, I come up with 50 mpg... But then they throw in a 6.67 multiplier. Not being able to come up with anything in engineering or science that would suggest that a Tesla should actually be advertised as having 333.5 mpg equivalent, I poked around to see what the 6.67 multiplier might mean. Turns out it is the multiplier used for any "alternate" fuel, and it exists only for political reasons, not for any reason related to the physics of the matter.

So if you are GM and building lots of 12 mpg SUVs you simply build the requisite number of 12 mpg "flex fuel" vehicles (which are considered 1/2 alternative fuel vehicles: ie 3.33 multiplier). Voila! -- each one of those they sell is good for 40 mpg. Of course, it is impossible to actually buy E85, because gas stations don't want to put in pumps that very few people will use. Thus, these 12mpg SUV's get 12 mpg, (and about 20% worse than that on E85, if they could find it) but are credited with getting 40 mpg.

Not directly related to over-unity... but my reaction to reading the law was the same as when I read about stuff where they throw in the over unity claim: ok, yeah, ok... WHAT THE F...!

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#101
In reply to #98

Re: Heating Water Through Friction

02/19/2008 3:52 PM

"...Not directly related to over-unity..."

Are you serious?!? This is EXACTLY 'over-unity' in its worst (encouraged by the authorities rather than prosecuted as fraud) form! Somebody needs a good hangin' is what...

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#105
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Re: Heating Water Through Friction

02/20/2008 3:02 AM

As the saying goes, "There's lies, damned lies, and fuel-efficiancy claims".

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#17

Re: Heating Water Through Friction

02/14/2008 12:20 AM

Dear Melanie.Massey, Please log on to You Tube and find the site "SPR Cavitation.

Dragon

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#20

Re: Heating Water Through Friction

02/14/2008 3:57 AM

Have a look here:-

http://cr4.globalspec.com/thread/17270

especially at Lapinbleu 's reply #1

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#22

Re: Heating Water Through Friction

02/14/2008 6:21 AM

You don't need friction in the sense of solid surfaces rubbing together (which would cause wear anyway). You can convert mechanical energy to heat by turbulent stirring as in joule's classic experiment on the equivalence of mechanical and heat energy. There's a description at: http://en.wikipedia.org/wiki/James_Prescott_Joule

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#23

Re: Heating Water Through Friction

02/14/2008 7:31 AM

My dear Melanie

I think you can not heat water even up to more than 5 degree through friction.I wish good luck to you.

Regards

C.S. PANT

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#25
In reply to #23

Re: Heating Water Through Friction

02/14/2008 8:57 AM

Someone who has used a works mobile fire appliance to pressure-test a factory water main during a low-demand period would tend to disagree here.....

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#26
In reply to #25

Re: Heating Water Through Friction

02/14/2008 9:08 AM

Just remember that you can't increase the energy of the water more than the energy you put into it (obviously!!) Heat is the most degenerate form of energy because it is the least ordered ,so converting any energy to heat is easy- you just need to dissipate it (in most applications, but not this one, that means wasting it!). So long as you put mechanical energy into the water (by stirring turbulently, for example) and no mechanical energy comes back out again, all the energy input will convert to heat.

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#28
In reply to #26

Re: Heating Water Through Friction

02/14/2008 9:21 AM

Absolutely! Seeing steam come out the back of this particular fire engine was a wonderful learning experience. There was lots of pressure, which was wanted, and the water wasn't going anywhere despite the pump running hard, which was a problem; the action of the pump's rotor was simply to heat it all up. Which is along the same sort of lines as the original post, really, though on a much bigger scale.

The fire officer operating the engine was getting more than a little concerned about the longevity of the equipment..............

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#29
In reply to #23

Re: Heating Water Through Friction

02/14/2008 9:54 AM
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#27

Re: Heating Water Through Friction

02/14/2008 9:17 AM

Hi Melanie,

FYI take a look at US Pat. 1,952,281 " Method and apparatus for obtaining from a fluid under pressure two currents of fluids at different temperatures" patented by Georges Joseph Rangue Mar.27, 1934.

Good luck on your endeavours and Happy St Valentine


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#32

Re: Heating Water Through Friction

02/14/2008 11:26 AM

Hi, this sounds like a great project for discovering all sorts of things or are you looking at it as a serious future water heater? Then take a look at the overall efficiency [energy put in at the beginning of the system (to drive the axle) against temp rise in the water] there are mechanical losses, an electrical element is hard to beat in efficiency at >95%.

Any way in answer to 'On an axle rotated by an elastic band, is it more effective to have the band level with the axle or on a different level?'

The belt drive (your elastic band) should be at right angles to the C/L [Center Line] of the shaft to be most efficient. Efficiency will not be effected by its 'orbit' position around the shaft.

'If I was to enlarge the diameter of the part of the axle being rotated by the elastic, what would the benefits be?'

If the drive 'wheel' [pulley / shaft diameter or number of gear teeth] is larger than the one being driven [the driven wheel] the output speed will be faster than the input speed [by the ratio of the pulley radius's] If it is the other way round the output speed / rpm [revolutions per minute] would be lower but have more turning power [torque]

Think of a bicycle gearing system, one peddles many times to easily cycle slowly up the hill.

The width of the band [belt] is relevant to the amount of power you wish to transmit, use a wider band or more of them to transmit more power, they will begin to slip if you overload them.

Lastly you may Google and find of interest FRICTION WELDING, two metals can be spun against each other or a tool to generate enough heat to melt them together. It shows how much heat can be generated by friction.

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#33

Re: Heating Water Through Friction

02/14/2008 11:55 AM

Hi Melanie,

I admire your courage and determination. Don't give up, even if practically you cannot achieve much. Trial and failure is a good way to learn, combined with reading. But remember: whatever experiment you do, stay safe!

To answer to your title-question: yes, it is possible to heat (voluntarily or not) water through friction, but in different ways than you think.

First way is to pump a flow of water through a large pipe connected to a much smaller pipe (1/4 or less diameter ratio). Friction between water and the wall of the smaller pipe generates heat. If the smaller pipe is a serpentine inside your can, than you may transfer that heat to whatever liquid is inside. Copper pipes are preffered. The only condition is to maintain the flow in a closed circuit.

Second way is to take the same pipe setup filled with water, but instead of having a flow inside, to generate sound-like vibration at one end and to plug the other end of the small pipe. Due to water compressibility, waves are traveling back and forth through the pipes. The smaller diameter pipe becomes hot due to thermo-sonicity (actually another form of friction). Go to wikipedia and search for sonicity. Sonic circuits can be calculated much like electric ones, as the discoverer of sonicity (inventor G. Constantinescu) proved. You can do some research at a library on this subject.

For your experiment, I would weld together some plumbing copper pipes (ask a plumber or someone skilled - don't play with the propane welding torch!) to make something like this:

The membrane (rubber from a wheel tube) can be pushed back and forth by a cam connected to a shaft that is driven by some rubber strip recoil such as this:

http://www.turnertoys.com/G1/balsa_model_airplanes3.htm

In a well-tuned setup and appropriate input power, temperatures of the thin tube as high as 300° C can be achieved (much higher than the boiling point of water inside!

A third way to generate (unwillingly) heat inside a fluid is through cavitation and diesel effect that occurs in high-pressure hydraulics when the working fluid is having air bubbles (aeration). You can google these terms just for learning purposes, but I don't think such materials (high-pressure hydraulic components) are available to you. A lot of safety issues are also related to this field.

I wish you good luck and please keep us informed on the progress of your project.

Michael

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#34
In reply to #33

Re: Heating Water Through Friction

02/14/2008 12:03 PM

Like your ideas - by the way did you catch the bit Melanie put at the end:

One of my goals with this project is to make it out of recycled and supercheap materials (e.g. old wooden sticks, elastics, old coffee cans), so please keep that in mind :)

only jesting.

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#73
In reply to #34

Re: Heating Water Through Friction

02/17/2008 9:35 AM

Hey JohnBob,

If interested to read more on Constantinescu's inventions and sonicity, take a look at this:

http://fluid.power.net/fpn/const/

Actually he lived in England, so you may find more information at the Admiralty library. George Constantinescu became famous for applying sonicity to a device capable to firing a machine gun through the propeller which brought a huge advantage to the British pilots in WW1.

Your reminder on Melanie's project is correct. However, we live in a time when especially reach nations are wasting so much that recycling mainly expensive materials, such as copper, is cheap and desirable. Just think how much copper plumbing can be recycled from demolitions in North America. We have enough technology and knowledge to help poor nations. It's just a matter of initiative and some political will.

Regards,

Michael

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#79
In reply to #73

Re: Heating Water Through Friction

02/17/2008 2:10 PM

Michael, thanks very much for you link, fascinating. I was aware of the 'Interrupter Gear' (aircraft are my 'thing') but not of the details or George Constantinesco; what a guy and a time.

I did not mean to be critical by trying to keep 'on topic'; from Melanie's point of view - to some extent I'm guilty of it myself! Others took it too much to heart, oh well.

I am also a keen recycler, so with you there. Copper actually gets a good price at scrap metal dealers - we had to strip a 500kVA 415/11kV transformer and got £400 (~US$800) for the 'bus bar copper'! As you say plumbing copper wastes in skips everywhere, often in the UK it gets collected and 'weighed in' There is a big demand in China for their growing economy, it goes over in container loads.

Regards, JohnBob

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#86
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Re: Heating Water Through Friction

02/18/2008 12:40 PM

"...Copper actually gets a good price at scrap metal dealers..."

Too good! We've had numerous instances of people stealing all the copper wire/pipe out of transformers, air chillers, etc. One guy should be up for a Darwin Award - electrocuted trying to strip out a live power substation transformer. Somewhere on the order of 7KVA...

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#92
In reply to #86

Re: Heating Water Through Friction

02/18/2008 7:24 PM

On Over Unity (& engineering humour?)

I've got it, they are not just shearing water - it's atoms; down at the Fire Station, in a cupboard behind the showers it's a nuclear fission water heater; that's where the extra energy comes from! [an example of dry engineering humour with a spot of British sarcasm!]

….& Melanie - you can't call pushing a pencil a career, [now that's just me being rude & how I wind up our (v.skilled) draughtsman.]

Welcome to engineering.

p.s. EnviroMan, Hi. We got three quotes for scrapping our (dry, air cooled) transformers as we had two. Stripped the first one and split it between two scrappies to keep a good price- mistake, must have pissed off one of them as the other transformer got stolen 3 weeks later, before we had a chance to strip it down! So I know the feeling.

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#36

Re: Heating Water Through Friction

02/14/2008 3:25 PM

Hi Melanie:

I've been reading this entire thread, and I love your energy, and your idea. And I'd like to hark back to one of your early answers, to wit "I'm trying to do it cheaply" (Might not be a quote, but I think you'll agree I got the idea right), and another, having to do with third world countries. So let me suggest a modification of your original idea to apply the same principle, but deliver more of the energy available to the fluid, AND use a cheap and readily available fluid, in fact, any slurry made of water and the starches found in such staples as Corn, Manioc Root, Casava Roots, and many other staple foods of other cultures. We call the one we use Corn Starch, but the slurry that results from mixing them with water is called "Non-Newtonian", and nearly any stachy powder will make it. What makes it ideal is that when slow changing pressure is applied to it (gravity, a gradual increase in flow pressure, etc.) it behaves like water. But when any suddenly changing force is applied (impact, turbulence, fast moving frictive surfaces like the pebbles, or vains, in your experiment) it reacts by exhibiting increased viscosity.

So, in your experiment, put the non-newtonian fluid between the cans, and both cans inside another (to carry the fluid you want to pasteurize) and spin the innermost can. If you arrange the three concentric cans on a vertical axis, with the middle and outer cans open at the top to allow the (closed) center can, with its axle protruding out the top to be belt driven, the viscous fluid can cause friction between the inner and middle cans, causing the middle can to heat, and transfer its fluid out into the pasteurizing fluid. Then only insulate the outside of the outer can, but fill the inside of the inner can with clay, mud, cement, or whatever else will harden, and provide more stability, and more inertia (to minimize the constant jerking that could occur as turbulence alternately slows and releases the can as it spins).

If you secure the middle and outer cans together at their bottoms, and mount a bearing for the inner can on the bottom of the middle can, a framework mounted to the outer can will be able to hold an upper bearing, with the inner can's axle extending between the two. Remember that the bearings are going to experience side thrust, and this will accelerate wear to one side. Using a driver on two opposing sides of the axle, with independent driving bands coming from the two opposing sides could eliminate the effect, prolonging life, and allowing for more energy input if needed (two people peddling two bicycles, maybe?) Then apply your driving band(s) to the upper length of the axle, fill the area between the middle and outer cans with the fluid to be pasteurized/heated/boiled/etc., and you should be in action.

Then, to really make it work as a production number, install a petcock, like a garden hose faucet, in the lower wall of the outer can, and as the fluid is heated, you can drain it off, to be refilled from above.

Hot water at the campsite, anyone?

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#40
In reply to #36

Re: Heating Water Through Friction

02/14/2008 4:43 PM

The petcock is a brilliant idea, thanks!

Hmm.. The idea of using non-newtonian liquids is also very intriguing. My partner and I will definetly experiment with a corn-startch-water solution.

We'll also try experimenting with the inside canister spinning, as opposed to the outside one. My only concern is it'll make a mess because the outer can has no way of being completely sealed...

thank you again, though, I'll be sure to post any new ideas or advancements, look forward to pictures once the prototype is done.. :)

Melanie (&Duncan)

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#45
In reply to #40

Re: Heating Water Through Friction

02/15/2008 6:34 AM

<....look forward to pictures once the prototype is done...>

Yes please! That would be of great interest.

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#37

Re: Heating Water Through Friction

02/14/2008 3:51 PM

I think you have enough good info already from the previous posters, so all I wish to do is encourage your scientist-to-be-ness (you already are one, just nobody ever made it official by telling you so, but anyone who does science is by default a scientist). Also to congratulate you on registering here as a member rather than asking questions as a guest (we have SO many of them...), and coming up with such an intriguing project. PLEASE do let us all know what happens?

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#38

Re: Heating Water Through Friction

02/14/2008 4:29 PM

Yes sounds like a good project should be able to heat some water.

But here are some thoughts if you place the water in the cans and spin them then the water will be moving all so. May make a mess. How about holding the can stationary and rotating the friction plate against it.

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#41

Re: Heating Water Through Friction

02/14/2008 9:02 PM

Lots of great suggestion but this can be very difficult. Some university students tryed it with a bicycle and clutch pads to find out that the best athlete could hardly boil the water. Their conclusion was that they needed to have a good insulation and heat recovery from the exhaust to intake water (continuous flow system). They also found out that minimizing the volume of water and the heater was better as they could reach boiling temperature faster. They were looking at using only one or two cc with high intensity friction plates. Minimize shaft thermal conduction as it will be a major heat loss path.

Be careful with anything mechanical and with stored energy in springs and large rubber bands. Use strong guards around these parts.

Have fun!

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#42
In reply to #41

Re: Heating Water Through Friction

02/14/2008 9:10 PM

Well I have had it now the real deal will come out and you all will look up at me with anticipation and say why didn't I think of that. look on youtube and go to water hammer. End of story.

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#46
In reply to #41

Re: Heating Water Through Friction

02/15/2008 6:46 AM

<...a bicycle and clutch pads to find out that the best athlete could hardly boil the water....>

A weekend casual cyclist could sustain a shaft-work output of, say, 50-80W (50-80 joules per second) over time, with short bursts to, say 135W for hill-climbing, depending on age, personal fitness and self-motivation. Now, some of that power is going to be lost stirring air, partly with the movement of the wheels' spokes and tyres, and partly with the cyclist's movement through a four-dimensional spacetime that contains a viscous fluid. Another packet of power is going to be lost as friction in the bearings and the tyres where they contact the road surface.

A stationary cyclist is going to save the four-dimensional spacetime losses, though greater upwards convection is going to be needed to keep the cyclist cool.

So say 100W is available to reach and sustain boiling. In order for the water to boil, insulation must be sufficient at the boiling temperature for losses to be lower than 100W. While it could be achieved, it's going to be an involved process getting there.

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#53
In reply to #41

Re: Heating Water Through Friction

02/15/2008 3:00 PM

Very interesting, thank you very much for this :) I've heard of the bike experiment before, but not in any detail... I heard that after about an hour the demonstrater was sweating like mad and the water still hadn't reached 100degC!

One of the main focal points of our (Duncan&I) project is that we only have to heat water to 70degC, so this should make it easier to reach and insulate. We'll also try to make it more efficient, if possible, than the other design (however this might be difficult... doing a better job than university students??) by using simple gear/axle ratios and non-newtonian liquids (still to be tested).

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#56
In reply to #53

Re: Heating Water Through Friction

02/15/2008 3:40 PM

"...sweating like mad..."

Probably reached 100°F then, at least!

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#43

Re: Heating Water Through Friction

02/14/2008 10:23 PM

The ramming pump simply uses the momentum of a large flow of low pressure liquid to produce a low flow at higher pressure one. The energy is conserved (less the losses) but the water is wasted.

It works like the switching power supply in your computer, or the AC motor drives... Sorry Melanie, we got carried away here. I doubt that you are ready for a degree in power electronics. Maybe in a few years.

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#44

Re: Heating Water Through Friction

02/15/2008 6:23 AM

Good luck Melanie,

Remember to keep it simple. Forget about the friction per sé, just create turbulence in the water, and, insulate it well. The mechanical energy must get transformed into heat energy (otherwise where else will it go): look at the links to Lapinbleu and Joule. Keep frictional losses external to the energy exchange system to a minimum, again as per Lapinbleu: a single axis with drive source on one end and paddles on the other should work best; his idea of using a rear car axle from a scrap yard must be about as cheap as you can get.

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#47
In reply to #44

Re: Heating Water Through Friction

02/15/2008 6:57 AM

Hold on - an old car axle from a scrap yard, turned by hand, agitating the water to heat it up! I think I know the temperature rise, careful or they could end up with a large coffee stirrer.

I do not mean to sound negative to the encouraging young enthusiasm; just realistic. Sometimes we can all put in some good ideas but the sum of those ideas?

Lets support an experiment that is going to work. [& I know that's not helpful in itself, I'm just short of inspiration at the moment!]

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#48
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Re: Heating Water Through Friction

02/15/2008 10:38 AM

OK criticism accepted. We probably need to know more about how much water she wants to heat, and, what she wants to do with it. The referenced design (linked above by both Ken and myself), provided enough hot water to bath Lapinbleu's family every day using just a vertical axis wind turbine made from old oil drums.

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#50
In reply to #48

Re: Heating Water Through Friction

02/15/2008 12:55 PM

Was not meant to be as harsh as a criticism , if fact I meant to place it as a thread and not especially to you. I was looking at all these ideas - including sound producing heat then to see she is using hand power (& sticks) Some of 'our' suggestions are just not realistic, it's becoming a CR4 discussion rather than advice for Melanie (& Duncan) Thank you for the interesting link, fascinating.

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#52
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Re: Heating Water Through Friction

02/15/2008 2:59 PM

"...it's becoming a CR4 discussion rather than advice for Melanie (& Duncan)..."

Now, wait just one minute - I think a CR4 discussion IS advice for these two scientists. Or are they engineers? This seems like a bit of basic science research with a LARGE component of applied science construction. And the discussion here is just what they should be participating in. Much discussion, shared theories and information, some controversy, a bit of humor here and there, the same as in any science lab or engineering office I've ever been in. Only difference, it's all electronic. Maybe sometimes we are a bit harsher on ourselves than is really called for...

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#54
In reply to #52

Re: Heating Water Through Friction

02/15/2008 3:02 PM

You're absolutely right...

Don't worry everyone, the discussion being generated here is wonderful. I will probably end up making a website just detailing all the ideas in one space for you to see, as well as pictures and data from our prototypes. Later send me an email if you want to be credited!

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#55
In reply to #54

Re: Heating Water Through Friction

02/15/2008 3:37 PM

Thanks - there are few absolutes in this life, but if this is one of them, then I am happy to have it! I gave you a vote for back on topic, although since it's your thread, you should know...

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#57
In reply to #52

Re: Heating Water Through Friction

02/15/2008 3:40 PM

giant coffee stirrer was an attempt at humour - by me!. My point, I was thinking of things it was possible for them to achieve / construct. (e.g. old wooden sticks, elastics, old coffee cans), so please keep that in mind :) was what was asked.

Granted all discussions & debate is good, but we want to include these flourishing minds. It's not a biggy....carry on!!

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#58
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Re: Heating Water Through Friction

02/15/2008 4:01 PM

See post #54 by Melanie herself - it's ALL good! No worries.

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#59
In reply to #47

Re: Heating Water Through Friction

02/15/2008 9:55 PM

I don't think agitatingthe water is actually going to do anything, unless I go at really high speeds :o I mean, it would be the same as putting water in a bowl and beating it with an electric stirrer, which doesn't heat it up at all.

The heat is going to need to come from something else, e.g. the warm cans (they've been hitting eachother) or the non-newtonian liquid (yet to be tested)

Thanks for your input anyway...

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#61
In reply to #59

Re: Heating Water Through Friction

02/16/2008 7:33 AM

Think about it again Melanie: where do you think the mechanical (kinetic) energy goes if it doesn't end up as heat?

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In reply to #59

Re: Heating Water Through Friction

02/16/2008 7:44 AM

The energy used to agitate the fluid will produce heat. But you will want to avoid producing too many bubbles, as this increases the rate of evaporation. This is why you might in principle wish to use vanes that are entirely under the surface of the water.

Personally, I would avoid any energy-dissipation method that involves banging cans together, as the damage generated is likely to exceed the useful heat produced. The same applies to friction between the cans - the surfaces are not designed for this, and the plating would soon flake and then act as a supplementary abrasive.

Energy dissipation in a fluid remains the least damaging way of converting mechanical energy to heat. The secret is to minimise the gap between the surfaces that "shear" the fluid*, and of course to maximise the areas of these surfaces. That will maximise the resistance at any given speed differential. With luck you may even find you don't need a non-Newtonian fluid to generate the optimum force.

*It may be a paradox, but cavitation will normally occur at lower differential velocities when the gap is large than when it is small.

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#64
In reply to #59

Re: Heating Water Through Friction

02/16/2008 9:46 AM

Hi Melanie & Duncan,

Re:#59 This is where we get theoretical; when one puts water 'in a bowl and beats it with an electric stirrer' the agitation will rise the temp ever so slightly, as stated the energy has to go somewhere. It will go to movement (the majority) but also sound, heat and stored potential. The atoms produce heat as they pass / forced over each other just as you get heat when rubbing your hands together. Your can / water heating experiment is extracting / collecting the heat produced during this process.

Now some how a post I entered earlier never arrived, so in addition: [sorry ]

May be I have not fully understood your driving method, you say: [at one end] The elastic will be hooked to the ground or some other object (e.g. a tree). Do you mean just hooked over a branch, I am afraid that way you would have a lot of drag, friction wasting energy, but you could replace this end with a pulley 'hooked to the ground or some other object.' Why not mount your can / pivot firmly to the tree then move the axle / drive wheel away from the tree to keep the drive belt [elastic bands] tight.

I do wonder about your drive system, it is important to get as much energy to the cans without loosing in on the way with drive losses. That is why possibly starting with a bicycle is handy as it is efficient as one can easily get, plus you have a gearing system. If you mounted the cans & their pivot base firmly you could use the bicycle wheel / tyre directly on the outer can to drive it, rather like driving a wheel dynamo.

Re:#8 Also have I misunderstood your statement - 'wind energy is a very expensive commodity' it's free surely? The best part (as long as there is wind) is it will go on putting energy into a system night & day so the small inputs mount up, with hand power one is restricted.

Re:#13 Cotton (when it is dry) has a fairly good factor of insulation, it's the evaporation of the water removing the heat when you get wet sailing. Try wool cuttings or loft insulation [but please not the glass fibres type!]

I am sorry, my posts tend to be so long zzzzzzzzzzz

p.s. Nice example Guest #63

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#70
In reply to #64

Re: Heating Water Through Friction

02/16/2008 10:03 PM

No, long posts are great, thanks :)

Well I mean to say that wind power will have expensive startup fees, with the machinery required to both generate the energy and then convert it to electric.

I dont think we'd be losing much energy by hooking it to a tree... the tree won't be driving it or anything... just there to hold the elastic in place..

I'll write some more later i have to go...

thanks again.

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#74
In reply to #70

Re: Heating Water Through Friction

02/17/2008 11:50 AM

I'm puzzled: if the objective is hot water, why would electricity be involved? Just have an insulated tank the appropriate size, and convert the mechanical energy directly to heat.

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#75
In reply to #74

Re: Heating Water Through Friction

02/17/2008 11:54 AM

Please remember that Duncan & I are trying to be as cost-efficient as possible.

This just doesn't seem plausible with the available means.

We have already state that we are not interested in wind energy. Thanks.

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#76
In reply to #75

Re: Heating Water Through Friction

02/17/2008 12:16 PM

I've no problem with your not wishing to use wind power - it may well be a sensible decision; but I was simply pointing out that post #70 gives a reason for high cost that doesn't hold water (should that be wind?). The habit of properly reasoned decisions and explanations is well worth developing (as may be that of not jumping down peoples throats).

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#77
In reply to #75

Re: Heating Water Through Friction

02/17/2008 12:48 PM

I think the guest's point is that the fewer energy conversions, the better. His idea is well-supported by thousands of observations in engineering and science. It doesn't matter if you use a windmill, a human, a dropping weight, or a donkey to provide the mechanical energy... the most efficient means of energy conversion is the most direct. If you want to go from mechanical energy (wind, hydro, human power turning a crank, etc) to heat, then the most efficiency way will be to do so directly.

In Joule's apparatus above, all the potential energy of the falling weight is converted to heat in the water. It's not magic -- the energy cannot simply disappear. His tank does not appear well-insulated, but if it were, and if the shaft were relatively small, of average thermal conductivity, and also insulated, then the efficiency of mechanical energy to heat would be very high. Anything you put in between (such as an electrical generator) will simply lower that efficiency.

You might take a look at my post #71 above, which I inadvertently marked as off- topic. It is actually squarely on topic.

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#78
In reply to #75

Re: Heating Water Through Friction

02/17/2008 12:57 PM

I think there is a little misunderstanding about what the guest #74 & I meant by wind power, you can power devices direct - such as water pumps in a field for irrigation. Wind power does not mean you have to produce electricity first & then use that electricity. As in the Lapinbleu setup.

However I take you point about cost / expensive start-up fees ( it was even me who brought it to others attention! ] So it is not for the moment but it could be an alternative way of driving it. This would mean one was producing heat why you were away. Call it a future development, these are worth thinking about during early stages as they may affect the way you construct you prototype / first model for future experiments. [A lesson I learnt in Research & Development work]

Sorry, I am still confused about this tree and the elastic band! I know 'the tree won't be driving it or anything', but if the band is just slipping round the tree / branch it will eat up energy, you will be actually heating up the tree branch - this is wasted energy. A cheap pulley from a sailing boat would be much more efficient. Maybe I have misunderstood the setup. Note: (thank you Ken) see the way the pulley is used in the drawing above to save energy loss. The cord is not simply passed over a bar.

[ p.s. In reply to #76 - hopefully we are adult enough to accept a direct answer, I am sure it was not intended to offend, re:'Thanks'.]

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#71
In reply to #59

Re: Heating Water Through Friction

02/16/2008 11:43 PM

Ah ha! A reasonable misconception, but you really must read about the early work-energy equivalency experiments of Joule. Provided the water is in a closed container (with a small opening for a shaft) then any heat lost to evaporation is regained through condensation. All the energy that goes into stirring the water must raise the temperature of the water, and if the outside of the container is well insulated, the heating effect can be very efficient.

In the rubber industry, they mix rubber with carbon black, some other dry chemicals, and some oil. It all starts at room temperature. A significant problem is that the rubber gets so hot from being mixed, that the stuff occasionally catches on fire. (Once on fire it is really difficult to put out.) Some of the friction is rubber against mixer, but most of it is the rubber's internal friction, molecule against molecule.

If you used a windmill (a vertical shaft one being particularly useful for this sort of thing) your overall efficiency in heating the water could actually be slightly better doing it directly (through stirring) than doing it by driving a generator which then powers an electrical heating element. A generator that is consistently high efficiency over a wide range of speeds is unusual and expensive.

There is a great physics site that goes over things like work, force, torque, power, energy, the laws of thermodynamics (which I will expect you soon to be able to recite in your sleep) etc. If the windmill (or whatever drives this) is lightly loaded (in other words if it easily stirs the water) the amount of torque required is low. That means, for a given speed, the power is low, so the water is heated slowly. On the other hand, if the torque is high (because of many interleaved vanes, for instance, with the water being sheared vigorously) then the power going in is higher and the rate of temperature change is greater too.

If you've ever paddled a kayak fast, you know that a lot of energy car be transmitted through paddles. As you ride down the road behind a power boat on a trailer, consider that that relatively small propeller transmits 100 hp or more into the water.

Wind power increases with the cube of wind speed, and roughly in proportion to the size of the thing capturing the wind energy. A used 55 gallon drum is the standard thing to use for building a nearly free Savonius wind generator, but you wouldn't need to start that big.

A dynamometer, used to measure the output of engines, traditionally uses a brake, just like the disc brake on a car. These get blazing hot in no time, because they must absorb the power of the engine. If you imagined for a second that an engine was 100 percent efficient (they are anything but), then you could make the brake equally hot by 1. running the engine and trying to stop it with the brake or 2. taking the same amount of fuel consumed by the engine, and instead simply lighting a fire under the brake (and housing the brake so all the heat goes into it).

Along the same lines: (ignoring the inefficiencies) if you crank a handle that drives paddles through a step up gearbox, you will be converting the energy of some number of calories (actually kilocalories in food) into heat in the water. As you can guess, in this case we can't ignore the inefficiencies realistically -- your body will be giving off a lot of heat to the environment around you. You'd do better to take the cookies you eat for the required energy, and simply set fire to them to heat the water.

You are embarking on an interesting and worthwhile project, and I wish you the best of luck. The world needs far more scientists, and you will be a great one.

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#128
In reply to #59

Re: Heating Water Through Friction

02/26/2008 3:57 AM

<....it would be the same as putting water in a bowl and beating it with an electric stirrer, which doesn't heat it up at all...>

Actually it does raise the temperature, though the rise is so small it hasn't been detected yet!

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#49

Re: Heating Water Through Friction

02/15/2008 12:33 PM

If I may be so bold gentlemen, Melanie is a 15 year old scientist who can think on her feet! If it's for countries like Africa, then in the middle of nowhere, where are they going to find large quantities of water? If the supply is from a well which is driven by a small windmill, why not use the power of the mill to drive the system? If it's a hand pump then the quantity of water will be small so I assume you could have a hand cranked small tin can arrangement which may hold a few litres.......wait....I've got it!

How about two horizontal rollers that can be driven by any bike? The axle of one roller is connected to the can system with the Newtonian fluid! When you have finished with it, ride home on the bike! It's just a simple wood frame with a couple of rough turned wooden logs with any odd round bits of bar for the stub axles, one being a bit longer with a wooden pulley (or car pulley, etc) attached to the end! The band (belt) could do a 90 deg twist on to another wooden pulley (or car pulley, etc) and drive the scaled down 'system'!

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#51
In reply to #49

Re: Heating Water Through Friction

02/15/2008 12:56 PM

If on the other end of the roller you had a big round weight then once you got some good inertia going this would help!

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#60

Re: Heating Water Through Friction

02/16/2008 4:18 AM

Hello,

On an axle rotated by an elastic band, is it more effective to have the band level with the axle or on a different level?

Precisely level need not be but do twist the band, not so makes and "X" but that there is a twist in each side between the shafts. This technique eliminates vibration of the band, prevents the band from wandering and loss of energy.

Keep your point sharp...

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#67
In reply to #60

Re: Heating Water Through Friction

02/16/2008 2:05 PM

Now that, 'Twist the band, 1/2 turn on each side, to eliminate vibration ..", is one I would never have thought of in a million years, and yet I've seen just that happen, in the past. That is one excellent thought.

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#104
In reply to #67

Re: Heating Water Through Friction

02/19/2008 8:05 PM

Thanks

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#63

Re: Heating Water Through Friction

02/16/2008 8:53 AM

Have you ever noticed the heat generated by a bicycle pump ? You could modify the flexible adaptor, so that 2 pumps are connected 'nose-to -nose'. The coupling could be enclosed by a water filled container. If desired, the pump could be connected by a linkage to a bike. I don't think you'll get a lot of hot water, but it could work - try pumping a pump with just an adaptor on the end, the metal part soon gets too hot to touch to the lips.

Kris

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#68
In reply to #63

Re: Heating Water Through Friction

02/16/2008 2:08 PM

Kris:

And why, pray tell, would you kiss the adaptor? (Isn't that what "touch to the lips" brings to mind?) Are you in such ecstasy over having fixed the flat as to lose all control? Get a grip, man!

Sorry, couldn't restrain myself. Ecstasy, I guess!

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#72
In reply to #68

Re: Heating Water Through Friction

02/17/2008 2:08 AM

Tee hee.....I just took the KISS principle to it's obvious limit ! The valve get's real hot as well. My air-like diversion may not be what Melanie had in mind, but it produces small quantities of high grad heat. It could be easily fabricated, but I think producing enough hot water for a cup of tea would be difficult whatever method was used. My secret lair is still in progress so I don't , alas, have time to construct my proposal.

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#85
In reply to #72

Re: Heating Water Through Friction

02/18/2008 12:33 PM

"...My secret lair is still in progress..."

Wot, like the Bat-Cave, then? Holy acorns, skwirrelman!

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#94
In reply to #85

Re: Heating Water Through Friction

02/19/2008 2:05 AM

And there was me thinking nobody would notice my wordplay upon 'Flat'. My White cat escaped and took up the name Del !

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#65

Re: Heating Water Through Friction

02/16/2008 10:01 AM

just a couple of extra "two cents" -

much of the discussion is pointing to the need for compression during the operation to convert the mechanical energy - given that you can provide some continuing energy aka the elastic band, belts, horizontal bicycle chain etc -

Plastic materials can be heated several hundreds of degrees in a 'rotary extruder' which relies on circular segments not necessarily concentric to one another to induce compression during the 'spin cycle' - the same thing that happens when a volume of material is squeezed quickly through a small orifice - some of the mechanical energy required to increase the speed with which it exits (since you won't compress the liquid) is converted to heat -

your efforts are quite commendable - good luck; also be sure to involve someone around you as you achieve measureable and sustainable successes; someone who is trustworthly to help you produce a 'provisional patent' for your efforts which will set a date 'stake in the ground' for you to eventually patent any truly new and innovative outcomes - good luck

Jim Wilson

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#66

Re: Heating Water Through Friction

02/16/2008 12:33 PM

Hello everyone, me again, I'd just like to thank you all for your input! Its hard for me to reply to every post, but please know that I've read them all. There are some very brilliant ideas in here :)

I'll be putting up some sort of site with what Duncan & I have so far, just to organize the ideas that have been building up in this discussion board...

Thanks again!

Melanie

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#69
In reply to #66

Re: Heating Water Through Friction

02/16/2008 2:08 PM

Melanie,

You're a great addition. Please come back and participate as you can.

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#89

Re: Heating Water Through Friction

02/18/2008 5:26 PM

Hello everyone,

Duncan and I have decided to do a vertical design, as opposed to a horizontal one... it will just make it easier to load and unload with water. We have also decided to try the non-newtonian liquid idea, but if someone could give us a scientific explanation of this and how it works it would help solve our curiosity about it :)

We have some more questions!

  • Because of the now vertical design of our system, we require bearings. Where can we buy these? (We're thinking maybe 1-2 cm diameter ones). Duncan and I are located in Toronto, Ontario, Canada, so local places would be nice. The alternative would be ripping them off my old skateboard... thoughts on this?
  • We did some calculations, and found that to heat 1 kg of water (or 1 L) we need to use about 57 calories of energy... this seems like a lot! How will we do this using rubber bands?
    • If not, we have decided to first heat the water using solar energy (which will also expose it to UV and kill more bacteria) before pouring it into the machine. This may be a little difficult to test because of the freezing Canadian winter occuring right now, but I'm sure we'll find a way around it...
  • Important: We're going to need a LARGE can, preferably resealable. Any ideas? (This is probably the most important part so far, as we can't begin experimenting without one!!)
  • Does anyone have thoughts on insulation? We're thinking of using some old stuff found in my basement, maybe clothing, but we might be able to find some of that fluffy pink insulation from old renovations... we'll tie it on with string and maybe use some glue (contact cement or apoxy)
  • Are there any thoughts on stopping leakage? Because of the vertical design both the water and non-newtonian liquid solution may start to leak. An airtight bearing sounds good but its hard to locate at the moment. Ideas for seals?
  • Any other suggestions are much desired :)

Thanks a bunch. We will post pictures of the first prototype soon, hopefully before friday.

Melanie (&Duncan)

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#90
In reply to #89

Re: Heating Water Through Friction

02/18/2008 5:46 PM

For the bearings, how about the headset on a push bike? Adjustable, and you could cut the handlebars off and ram a bit of broom handle into the hole to be a drive shaft of some sort! If you could modify the forks a bit, then you could attach the can with all the vanes to it! And as a bonus, it even has a frame attached for supporting the whole assembly!

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