Sippy Bird Experiments.

Discussion on Stirling or "hot air" engines (all types)
Tom Booth
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Re: Sippy Bird Experiments.

Post by Tom Booth »

Probably it could operate an air-lift spiral pump.

fig19.jpg
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https://lurkertech.com/water/pump/tailer/#xtocid213215
Fool
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Re: Sippy Bird Experiments.

Post by Fool »

Excellent link. Perty much read the whole thing. That IMHO, is a good introduction to how good science should be done and documented. Not perfect, but a good introduction. Good link, thank you very much.

That pump could be used. The reciprocating motion of the bird would need to be converted to rotary motion.

I just realized I should have included a link to the Wikipedia page on the drinking bird. Not surprisingly, it is very close to my opening post. It misses Tom's fanning of the evaporative head by bobbing.

https://en.m.wikipedia.org/wiki/Drinking_bird

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Tom Booth
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Re: Sippy Bird Experiments.

Post by Tom Booth »

Another option might be to just have the bird, on the upswing, bump it's tail bulb into one of these, or some similar small engine primer pumps

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In some videos, people have some problems with the bird swinging up and smashing it's glass bottom bulb into the water glass pretty hard and have to move the bird or glass further away, but then the bird can barely reach its beak over the rim of the glass.

Just position the button where it will hit that primer instead of the glass and maybe depress the primer button enough to pump a drop of water, or a bubble of air for an air lift pump.
Tom Booth
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Re: Sippy Bird Experiments.

Post by Tom Booth »

I think a more practical heat engine/evaporative cooler that could be more easily scaled up would be quite possible using a Stirling engine rather than the drinking Bird.

The P-19 "ultra LTD" ran on passive evaporative cooling for two weeks.

The water supply was maintained by simply hanging a cloth wick from a glass of water.

I think the output could have been easily increased by the addition of some fan blades to the flywheel.

I tried that with this engine recently but could not get enough ∆T for these regular LTD's. This one is just going on ice.

https://youtu.be/qRxh7YVb-M4
Fool
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Re: Sippy Bird Experiments.

Post by Fool »

I like the idea of whacking a pump when the bird stands back up. I'm just wondering how easy it would be to build one out of lightweight Saran Wrap that is smaller in diameter? It might be more effective and produce a higher pressure at lower volume. Even use a rolling diaphragm seal, out of Suran Wrap or silicone, in a small diameter tube and smaller piston. It could have a connecting rod that allows placement at the bottom of the supply tank.

It would potentially stop the bobbing effect. Just a single uprighting motion/whack.

The amount of water pumped up per time would easily show how many watts the bird can produce.

Painting the bottom bulb black, shading the head bulb, and placing in the sun, would increase the temperature difference. It could potentially produce more power. Same for LTD Stirling Engine running on evaporation and solar. Perhaps a mirror to redirect the solar to the bottom plate. It would need to be redesigned for that temperature difference.
Tom Booth
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Re: Sippy Bird Experiments.

Post by Tom Booth »

These arrived September 14th (5 days ago)

I set them up as seen here and they have both been going ever since, sharing the same glass of water.

So far they only seem to be using up about one teaspoon of water a day, between the two, or 1/2 teaspoon each.

I tried to get them synchronized, but they are each rather different. Probably hand blown glass, but one is taller than the other and due to that, they operate at different speeds and cannot be synchronized for any exact comparison testing.

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Sometimes I catch movement in the room out of the corner of my eye and am surprised when I look and see them still going.... For so long I forgot they were there.

They run noticeably more vigorously during the daytime when it is warmer vs. nighttime when it is cooler.

BTW, that 1/2 teaspoon does not differentiate between water evaporating from the birds heads and what is presumably evaporating directly from the surface of the water.

It might be interesting to cover the glass with cellophane and poke holes for the birds beaks to pass through. In actuality they may be using a bit less than what is required to keep the glass full

Maybe I'll just set another glass of water there for comparison.
Tom Booth
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Re: Sippy Bird Experiments.

Post by Tom Booth »

Alright, done

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Both glasses topped off at 12:30 PM.

I'm curious to see how much the birds actually increase the rate of evaporation, if at all
VincentG
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Re: Sippy Bird Experiments.

Post by VincentG »

bump
Tom Booth
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Re: Sippy Bird Experiments.

Post by Tom Booth »

These cheap dollar store spray bottles have very responsive little check valves I'll probably be using to rig up some kind of little pump

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Tom Booth
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Re: Sippy Bird Experiments.

Post by Tom Booth »

Probably not too surprisingly, it took a while to see a noticeable difference, but after a few days (33 hours so far) I think it can be clearly seen that, first of all, there is quite a bit of passive evaporation from the water glass without the birds. The glasses were both filled to the very brim to start out with.

Secondly, the water level in the glass with the birds has gone down a little bit more than the "control".

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Tom Booth
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Re: Sippy Bird Experiments.

Post by Tom Booth »

BTW, although comparisons are not possible due to the inherent differences, and trying to wet the birds head without ANY movement involved is near impossible, I have to say, I think Fool was correct in that the bird is sensitive enough to a slight ∆T it will start up from a standstill and run by just wetting the head, without swinging.

Exactly how much, if at all the swinging might contribute to, or help accelerate evaporation I have not been able to determine. Even manually dunking the head involves motion. Stoping the bird after a dunk, it's head is already cool from previous swinging.

At any rate, if the swinging is interrupted. The bird will start up again from a standstill, without much hesitation.
Tom Booth
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Re: Sippy Bird Experiments.

Post by Tom Booth »

Something that has been bothering me is that watching these birds run, they never seemed to swing backwards as far as I imagined they should, but on the return swing always seem to stop shot with the base bulb right between the legs.

Just a minute ago I noticed why.

There is a plastic tab at the pivot point that the crankshaft (? or whatever it's called) bumps into stopping the back swing.


https://youtu.be/hhGfz0iwcjQ


So really, there is already a considerable power loss. Energy being wasted just colliding with this bumper.

I might just clip off these tabs and see how much more of a back swing there is

At any rate, hitting the little water pump instead of this tab probably will make little difference to the birds operation.

I have the pump completed and it seems to work pretty well. I just have to construct some kind of frame to mount it on

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Tom Booth
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Re: Sippy Bird Experiments.

Post by Tom Booth »

I removed the tabs and widened the holes the bird pivots in.

It made quite a difference.

The bird with the stops removed swings back and forth further, faster and more continuously and also dips into the water more often.
Tom Booth
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Re: Sippy Bird Experiments.

Post by Tom Booth »

Fool wrote: Mon Sep 16, 2024 6:41 am I like the idea of whacking a pump when the bird stands back up. I'm just wondering how easy it would be to build one out of lightweight Saran Wrap that is smaller in diameter? It might be more effective and produce a higher pressure at lower volume. Even use a rolling diaphragm seal, out of Suran Wrap or silicone, in a small diameter tube and smaller piston. It could have a connecting rod that allows placement at the bottom of the supply tank.

It would potentially stop the bobbing effect. Just a single uprighting motion/whack.

The amount of water pumped up per time would easily show how many watts the bird can produce.

Painting the bottom bulb black, shading the head bulb, and placing in the sun, would increase the temperature difference. It could potentially produce more power. Same for LTD Stirling Engine running on evaporation and solar. Perhaps a mirror to redirect the solar to the bottom plate. It would need to be redesigned for that temperature difference.
I tried several primer bulbs. Most are much too hard rubber to be compressed by the bird at all, but these black rubber type are quite soft and compress very easily:

667460 Primer Bulb for Compatible with Toro Lawn-BOY 66-7460 Replacement Stens 120-440, CCR-3650, CCR-1000, CCR-2000, FSL90-0071 Snowblower Parts (5 Pack) https://a.co/d/gXKeGzz

If that doesn't work, I might try some of your other ideas.

The primer bulbs have a hole in the middle of the bulb but that can be closed with a piece of tape or something.
Fool
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Re: Sippy Bird Experiments.

Post by Fool »

Thanks for doing the lab work. I want to retract my earlier doubt that it won't pump enough water to keep the glass full. With your evidence, it seems very likely that it could, even with a wide open top on the glass. I was wrong. Kudos for your work. Suran wrap over the glass with holes for the beaks would be easy to add and reduce superfluous evaporation.

It seems Dichloromethane is more dense than water, so, in my humble opinion, it should be able to pump a similar amount of water upwards a similar height for each cycle. This should be enough to top off the glass, even with all the efficiency losses the bird and thermodynamics would impart.

To investigate maximum internal lift (pressure difference), the birds motion could be restricted, or blocked, and the dry head soaked with room temperature water from a closed water bottle. The maximum fluid rise could be easily seen, if it doesn't break suction by pulling all the fluid up into the connecting tube. It would be interesting to see how high it would rise with out motion, and later with a fan blowing. See if there is a difference between stationary and fan blowing (maximum pressure and temperature difference).

There are apparently two types of psychrometers, sling and stationary. Both.are a combination of wet and dry bulb thermometers. There seems to be only one chart and it's used for both indiscriminately. My assumption is that the two will have identical readings. Slinging must then just speed up the readings, not the maximum temperature drop.

People are convinced that the wet bulb, after slinging, should be read first before it starts warming up. It sounds like that is a myth. One could easily check that by reading the wet bulb twice. Or by slinging and not slinging. Right?

May your pump and check valve building go well. Thanks for your efforts.

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