Submersible Engine Design

[Sprocket]

It is a known phenomenon. The hydrogen pops out in bubles along the electrode only when it can overcome the ambiant pressure. The more the external pressure, the more the electrical energy needed for the electrolysis.

Does that mean that hydrogen cells in a partial vacuum would have a much higher output?

Furthermore, since hydrogen would have an obvious buoyancy-advantage, why not use a vacuum pump to suck the air & hydrogen out, feeding it either directly to another compression tank to increase pressure, or maybe straight to the submersible pump itself would do.  And as  powercat said, you could then also use the hydrogen to produce energy - maybe help run the vacuum pump!

[exnihiloest]

Does that mean that hydrogen cells in a partial vacuum would have a much higher output?
...

Of course, it is the corollary.


Hydrogen is lighter than air but both have a quite similar density when compared to water (air density is about 1/900th that of water at atmospheric pressure). So in water the buoyancy advantage of hydrogen over air is very very weak.

In any case, I don't see the interest of more and more complicated setup when the functioning is conventional and can be described by a hamiltonian which implies energy conservation.
Either a system is supposed to work according to the physics laws, and here it seems to me that it is the case, thus extra-energy can't be produced without a hidden source that would have to be specified, or there are new laws of physics (but why and which?) or there is a flaw in the laws or equations of mechanics, that however have been proved relevant and internally consistent for more than two centuries.

[TommeyLReed]

Lets start over again.

12^3=1729 cu/in
7.48 gal = 1728 cu/in
7.48*8.33=62.3 lb.
I forgot that the deeper you go, it will also increase upward force?
So really each cube at a deeper depth would have different force?
I'm trying to find the basic formulas to test each cube at 1ft,2ft,3ft,,,,,,10ft depth.
This would also mean less volume at a depth of 10ft, because as the cube rise the pressure make more displacement as it rise to the top.
This sound simple, but many factor to think about.

Archimedes' principle

A system consists of a well-sealed object of mass m and volume V which is fully submerged in a uniform fluid body of density ρf and in an environment of a uniform gravitational field g. Under the forces of buoyancy and gravity alone, the "dynamic buoyant force" B acting on the object and its upward acceleration a are given by:


Buoyant force
B=2gmpfV/m+pfV

Upward acceleration
a=g(pfV-m)/m+pfV


Tom

[TommeyLReed]

This submersible engine goes beyond Archimedes' Principle: 

Archimedes' principle is a fluid statics concept. In its simple form, it applies when the object is not accelerating relative to the fluid. To examine the case when the object is accelerated by buoyancy and gravity, the fact that the displaced fluid itself has inertia as well must be considered.[5]

This means that both the buoyant object and a parcel of fluid (equal in volume to the object) will experience the same magnitude of buoyant force because of Newton's third law, and will experience the same acceleration, but in opposite directions, since the total volume of the system is unchanged. In each case, the difference between magnitudes of the buoyant force and the force of gravity is the net force, and when divided by the relevant mass, it will yield the respective acceleration through Newton's second law. All acceleration measures are relative to the reference frame of the undisturbed background fluid.

Atwood's machine analogy
Atwood's Machine Analogy for dynamics of buoyant objects in vertical motion. The displaced parcel of fluid is indicated as the dark blue rectangle, and the buoyant solid object is indicated as the gray object. The acceleration vectors (a) in this visual depict a positively buoyant object which naturally accelerates upward, and upward acceleration of the object is our sign convention.The system can be understood by analogy with a suitable modification of Atwood's machine, to represent the mechanical coupling of the displaced fluid and the buoyant object, as shown in the diagram right.

The solid object is represented by the gray object
The fluid being displaced is represented by dark blue object
Undisturbed background fluid is analogous to the inextensible massless cord
The force of buoyancy is analogous to the tension in the cord
The solid floor of the body of fluid is analogous to the pulley, and reverses the direction of the buoyancy force, such that both the solid object and the displaced fluid experience their buoyancy force upward.
[edit] ResultsIt is important to note that this simplification of the situation completely ignores drag and viscosity, both of which come in to play to a greater extent as speed increases, when considering the dynamics of buoyant objects. The following simple formulation makes the assumption of slow speeds such that drag and viscosity are not significant. It is difficult to carry out such an experiment in practice with speeds close to zero, but if measurements of acceleration are made as quickly as possible after release from rest, the equations below give a good approximation to the acceleration and the buoyancy force.

A system consists of a well-sealed object of mass m and volume V which is fully submerged in a uniform fluid body of density ρf and in an environment of a uniform gravitational field g. Under the forces of buoyancy and gravity alone, the "dynamic buoyant force" B acting on the object and its upward acceleration a are given by:

Buoyant force

Upward acceleration

Derivations of both of these equations originates from constructing a system of equations by means of Newton's second law for both the solid object and the displaced parcel of fluid. An equation for upward acceleration of the object is constructed by dividing the net force on the object (B âˆ' mg) by its mass m. Due to the mechanical coupling, the object's upward acceleration is equal in magnitude to the downward acceleration of the displaced fluid, an equation constructed by dividing the net force on the displaced fluid (B âˆ' ρfVg) by its mass ρfV.

Should other forces come in to play in a different situation (such as spring forces, human forces, thrust, drag, or lift), it is necessary for the solver of problem to re-consider the construction of Newton's second law and the mechanical coupling conditions for both bodies, now involving these other forces. In many situations turbulence will introduce other forces that are much more complex to calculate.

In the case of neutral buoyancy, m is equal to ρfV. Thus B reduces to mg and the acceleration is zero. If the object is much denser than the fluid, then B approaches zero and the object's upward acceleration is approximately âˆ'g, i.e. it is accelerated downward due to gravity as if the fluid were not present. Similarly, if the fluid is much denser than the object, then B approaches 2mg and the upward acceleration is approximately g.

Tommey Reed