Water and gravity: look at this video

[sm0ky2]

Hi Sm0ky2,

Very clever design in your video!  Would you be willing to share more specifically how you envision moving the solenoid back and forth with minimal energy expenditure?  That solenoid is going to have to compress a fair amount of the air to increase the pressure enough to get the cartesian diver to overcome the resistance in the sprocket/chain mechanism. 

PS  I've enjoyed reading all your posts on this thread.  BTW, do you have any thoughts on the Plankz Buoyancy Engine?

Yes so:


Of course there are efficiency improvements that could be made:
For example we could reduce friction by using a belt/pulley system,
with a nylon or similar water-resistant belt, and the upper pulley fixed to
the drive shaft.


The compression mechanism itself, wether an electric solenoid is used, or
something like a linear motor, etc.:  is synonymous to a spring.
In that the energy used to compress the gas is returned upon decompression.
Reducing the energy input, essentially to frictional losses. This is Key.


The precise amount of compression required is a factor of the volume of buoyant gas
in the upper (flexible) portion of the bobber, the coefficient of the flexible material,
and the mass-ratio for the desired output energy.


This is a volumetric compression ratio based on the mass of displaced water between
the compressed and expanded states. The greater the compression ratio: the "heavier"
the bobber becomes during the non-buoyant stage, and the more gravitational force is
imparted onto the bobber as it falls. The same applies to the buoyant force, when the gas expands.


Height of the container provides a longer cycle-time, meaning the force acts on the drive shaft for
a longer period of time, each half-cycle, for (roughly) the same compression force. (+in / -out)
The important thing to take away from this is the fact that energy in and energy out (at the solenoid),
balance each other out. The output energy obtained at the drive shaft is purely gravitational.
(minus system losses)


P.S.:
My examination of Plank's ideas, the best attempts i have seen use a compressed gas,
introduced beneath the water chamber. This removes the loss of water
(which, is my understanding of the technical problems in Plank's original design)
I have NOT given this situation a full analysis, in terms of the energy required to compress
the air, beyond the pressure exerted on the bottom of the water tank, in comparison to the
Buoyant force obtained over the height of the water column. However, in practical applications
this seems to require more energy in, than out.
If i were to make an attempt at this, i would use flexible (expandable) vessels to harness the
compressed air, thereby regaining some of the pressure at the top side. There are of course technical
difficulties in terms of valves, etc. to make such a thing possible.

[MT]

I'm open to any opposing theories, constructive criticism,
Or idea that could advance this area of science.


Here's another gravity engine i  designed


https://youtu.be/jv9lQVZ4tUM

Hi sm0ky2
like your idea, have even believed in it for a while but I see a problem with retrieving back energy inputted in solenoid. As diver sinks deeper, air cap is further compressed by water pressure. At the bottom acts on air cap not only pressure exerted by solenoid but also whole water column above diver. This means air cap has smaller volume than it had at the top. Smaller air cap volume means water level is lower than it was when diver was at the top. And lower water level means less pressure which means less energy pushing solenoid back to initial position.

[MT]

To better illustrate issue with this design:


1. bottle has initial pressure P1 of the air above the water.
2. Solenoid increases that pressure to P2
3. Diver loses buoyancy and descent to bottom
4. Hope you see that air cap on diver is exposed to higher pressure at the bottom than it was on top
5. Less air cap volume causes water level to drop causing air pressure in the top of bottle to drop to P3


I think as P3 is less then P2 we cannot fully retrieve energy inputted to solenoid.

[kolbacict]

As diver sinks deeper, air cap is further compressed by water pressure. At the bottom acts on air cap not only pressure exerted by solenoid but also whole water column above diver. This means air cap has smaller volume than it had at the top. Smaller air cap volume means water level is lower than it was when diver was at the top.

If we take two divers in one aquarium. And connect them mechanically with the necessary interaction.
When one sinks and contracts, the other will rise and expand. The water level at the top will not change.

[Beginners Mind]

Sm0ky2 - Thanks for your reply.  Not withstanding the further comments about possible problems recapturing energy from the solenoid, I'm still puzzled how nearly all the energy powering a solenoid in this situation can be theoretically recaptured.  The plunger would need to be held either in or out, depending on the solenoid's orientation, for a period of time during which there will be I^2R losses in the coil that can't be recaptured, won't there?  Please correct my thinking if I misunderstand.  Thx.