Hydroenergy: strong symptoms of a scam

[exnihiloest]

Hydroenergy Revolution LLC (http://hydroenergyrevolution.com/) claims a free energy machine. The underlying principle called "Travis effect" is given in this video: http://www.youtube.com/watch?v=0JUj42h6j7Y
See particularly the time range: 1:00 - 1:50.

A cylindrical bucket is inverted and immersed in water, partially filled with air. A weight placed above sinks it down to the aquarium bottom. We deduce that the weight is more than the Archimede's thrust.
An identical bucket, filled with less air and provided with the same weight, is immersed in the same way, but it can slide around a concrete cylinder. We observe that air redistributes itself around the cylinder, that the thrust depends on this redistribution, and that there is a balance position. If the Archimede's thrust of the first case is equal to the weight of the volume of displaced water, in the second one it is (apparently) higher.
Did we gain energy?

The important thing to retain is that the pressure depends on the depth. The air pressure is equal the water pressure existing at the air/water interface. When the air redistributes itself around the concrete, the air/water interface is lowered, and consequently the air pressure is increased. It becomes more than when there is no concrete. Therefore the Archimede's thrust is stronger and balances the weight. The difference between the two cases comes from the reshaping of the volume of the immersed object, due to the air redistribution. This is as if we had two objets of different shapes: the two cases can't be directly compared.

Now the question is: can this reshaping be the source of free energy?
We would have free energy if the raising of the bucket of the second case could be done at a less price than that of the first case, which is the normal case.
To raise the bucket with its weight, we need to inject compressed air. For the bucket to rise a heigh h, we need to inject an air volume h*S where S is the inside section of the bucket. This is true for the two cases: if the bucket rises, the added air will have to fill the space between the top of the concrete and the top of the bucket, i.e. an identical volume as for the raising of the bucket without concrete! So the work to provide compressed air (which is dW=P*dV), will be the same in the two cases.
I came to this conclusion with the help of 2 independant physicists who gave the same verdict, seeing the flaw very rapidly.

Obviously the video is presenting a conventional effect in a fallacious way. I can't believe that the authors would be unaware of the real principle of the effect. And so I recommend to not invest in this company.

[BEP]

In the video he says " can two different volumes of air produce the same amount of lift".

At that point I knew what would happen in the rest of the video.

Of course two different volumes of air can produce the same amount of lift.

Gravity holds the concrete down while it displaces water.

If he changed the experiment to have the two displacement devices connected by a balance fulcrum he could better see the action. This would bring the concept closer to a motor by controlling pumped and released air into one chamber.

[exnihiloest]

In the video he says " can two different volumes of air produce the same amount of lift".

He said this because it is true but not relevant (he is trying to divert the attention, like a conjuror).
The difference comes from the different mean depth of the air volume.

At that point I knew what would happen in the rest of the video.

Of course two different volumes of air can produce the same amount of lift.

Gravity holds the concrete down while it displaces water.

If he changed the experiment to have the two displacement devices connected by a balance fulcrum he could better see the action. This would bring the concept closer to a motor by controlling pumped and released air into one chamber.

The principle is that of ballasts that we encounter in boats and submarines.

[GibbsHelmholtz]

Interesting...


If PV=nRT
P pressure
V volume
n air amount
R constant
T temperature

n goes down makes V go down while everything else remains constant.  We have the same pressure, but lift is pressure x surface area therefore surface needs to redistribute.  I'll think about what it has to do with buoyancy.

[exnihiloest]

If you put twice the quantity of air in a box of twice the volume, sure the pressure and all other things remain the same.
It is like to close/open a valve in a wall separating two parts of a box containing air.

[EMdevices]

EX,  thanks for bringing this topic, I find it very interesting.  

They are obviously demonstrating in the video just a STATIC case, a weight holding down the glasses.   In a DYNAMIC  process or a cyclical device like the otto engine,  we might realize that energy balances out.

For example:   Stefan Hartman's comments on the video make the point that less air needs to be injected in the glass with the cylinder inside.   Ok, that's true.    However,  the pressure profile as the air is injected is different for the two cases.    In one glass we inject MORE air at LOWER pressure, and in the other LESS air at HIGHER pressure.   The pressure profile is linear so we need to integrate.   If we integrate we find that the energy injection is EQUAL FOR BOTH CASES.

some might be wondering why the pressure is not equal, and that's because the water depth at the interface to the trapped air is not the same.   Why is this water level not the same.   Well, because this is needed since the water interface area is smaller when the cylinder is present.  So smaller area needs higher pressure to generate the same force.   Well known formula used to design the hydraulic brakes on every car:    F = p A 

EM

[GibbsHelmholtz]

I don't see how the two pressures different.  Actually, the one on the right should have less pressure since it is closer to the surface. 

[GibbsHelmholtz]

I think I see it now.  This effect is an inverted view of a glass of water.  It is the same as putting the cylinder inside a glass of water sitting in air. 


There are buoyancy and gas expansion at work.  The buoyancy is due to differential pressure.   In a traditional steam turbine, there are two process that gives energy to the turbine.  One is pressure differential between inlet and outlet and the other is thermal expansion of the steam.   Expansion of the gas require energy and we give this energy through the boiler.  What if we don't have to provide the energy for expansion?  If we have air expands at room temperature, energy from ambient is required for this to happens.  We then have a gain. 

[GibbsHelmholtz]

I just thought of this experiment.

Let's say we have a container with air inside.  A volume of air is trap inside a weightless sphere.  Pressure is then applied to compress the air.  The density of the air changed except for the volume contain inside the sphere.  The sphere rises under buoyancy.  When pressure is release, the sphere falls under negative buoyancy. 

[BEP]

Gibbs,

Think of that experiment with the container having nothing but a vacuum inside. Buoyancy changes by the weight of the water displaced and total weight of the displacing body. If that body is lighter than the water it displaces it will rise. It doesn't matter what is inside, air, vacuum or concrete.

I think that your thought device would sink when it compressed the air by decreasing its own size.  

-------

OOPS!

Sorry. I didn't understand your post the first time. My statement above doesn't apply to yours.

[GibbsHelmholtz]

Gibbs,

Think of that experiment with the container having nothing but a vacuum inside. Buoyancy changes by the weight of the water displaced and total weight of the displacing body. If that body is lighter than the water it displaces it will rise. It doesn't matter what is inside, air, vacuum or concrete.

I think that your thought device would sink when it compressed the air by decreasing its own size.  

-------

OOPS!

Sorry. I didn't understand your post the first time. My statement above doesn't apply to yours.

WaveW,

Sorry my wording is complicated.  I tried to find what energy is given to buoyancy.  So far I cannot detect any input into this system while the little sphere moves up and down.

[exnihiloest]

I just thought of this experiment.

Let's say we have a container with air inside.  A volume of air is trap inside a weightless sphere.  Pressure is then applied to compress the air.  The density of the air changed except for the volume contain inside the sphere.  The sphere rises under buoyancy.  When pressure is release, the sphere falls under negative buoyancy.  

This is a real working principle, already known. An improved version exists and is called "ludion" in French (an invented name that evokes gaming).
Instead of using a small container of constant volume/pressure inside a wider container containing a medium whose the volume/pressure can be controlled, the option is to use a small container of variable volume/pressure containing a highly compressible gas (air), and floating inside a container filled with an incompressible fluid (water): the increase of the pressure of the fluid is transmitted to the small container due to the incompressibility of the fluid. The small container (or only its inside air volume, depending on the building) shrinks under the pressure. It follows that the Archimede's thrust becomes not strong enough to sustain the small container, which sinks. When the pressure is released, it raises again.

http://www.youtube.com/watch?v=c5JJzS91q9o

It works according to the physics laws: no free energy.

[exnihiloest]

Sorry my wording is complicated.  I tried to find what energy is given to buoyancy.  So far I cannot detect any input into this system while the little sphere moves up and down.

When the floating sphere is at the top and you decrease the pressure, you can't recover all the energy that you put for compressing the volume when the sphere was at the bottom. The pressure is more at the bottom than at the top. Therefore when the sphere is at the bottom, it has displaced above it its own volume of air. So you have to compress a larger volume of less compressed air.

[BEP]

Buoyancy would only depend upon the amount of water displaced and the weight of the displacing object. Hence, a sphere having a fixed volume while containing a vacuum would float better than while containing air. While containing compressed air it would have less buoyancy than while having uncompressed air.

[GibbsHelmholtz]

When the floating sphere is at the top and you decrease the pressure, you can't recover all the energy that you put for compressing the volume when the sphere was at the bottom. The pressure is more at the bottom than at the top. Therefore when the sphere is at the bottom, it has displaced above it its own volume of air. So you have to compress a larger volume of less compressed air.

Thanks for the research and video.  Yes, the two experiment are the same.   The pressure is recovered, all of it.  When you compress a piston or spring, you recover all the energy under ideal situation.  When the sphere is at the bottom, it is equivalent to the piston or spring at its maximum displacement.  The pressure required is proportional to the height at any point.  If you have larger volume of air, you need less pressure.  Overall, you gain buoyancy force.

[exnihiloest]

...An improved version exists and is called "ludion" in French
...

I built one. It's easy. Just for fun.
http://www.youtube.com/watch?v=rbSAqGQDUn8

A strange thing happened. The pressure inside the bottle increased by itself and after one or two hours, the floating cylinder had thunk at the bottom. I opened the bottle to free the pressure, and then I closed it again. The phenomenon happened a second time yesterday. But this morning, it was still floating.
I don't know why.

[Peterae]

Barometric pressure change acting on it's outer surfaces and surrounding liquid, looks like you have just invented a free energy machine by accident  

[BEP]

http://en.wikipedia.org/wiki/Galileo_thermometer

[GibbsHelmholtz]

I built one. It's easy. Just for fun.
http://www.youtube.com/watch?v=rbSAqGQDUn8

A strange thing happened. The pressure inside the bottle increased by itself and after one or two hours, the floating cylinder had thunk at the bottom. I opened the bottle to free the pressure, and then I closed it again. The phenomenon happened a second time yesterday. But this morning, it was still floating.
I don't know why.

I've been thinking if we make the bottle really long.  There is a point of no return.  After certain depth, the float will attain negative buoyancy and continues to sink even pressure is released.  Let's say the pressure for the float to sink is Psink .  Initially, the float is on the surface:

Pwater + Psystem = Psink

Pwater= 0 initially, so the applied system pressure equals to Psink.  However, there is a water depth that Pwater will be greater than Psink.

Pwater + 0 = Psink
Pwater = water density x gravity x height

At this depth, the float can no longer come back up.  I'm thinking could this be similar to the nuclear force where things cross the point of no return. lol

[GibbsHelmholtz]

I'm recently investing more time into this subject.  

I want to promote the spiral pump as an OU pump, however, I'm still dissecting the pump's mechanic. The spiral pump may have the same working principle as a screw pump.  This idea is not new in history.

http://todayinsci.com/Books/MechApp/chap23/page38.htm



I'm heading in the direction of Newton's law.

For static:  Summation of force = 0
Dynamic :  Summation of force = ma (mass x acceleration)

This is similar to the infamous, or famous Faraday vs Kirchhoff. lol  There is argument that it is no different to stand in an elevator in space that accelerate 9.8m/s or stand in an elevator on earth non moving, but one has acceleration component while one is does not.  It seems that the acceleration is... free.  What if we are to redirect that acceleration normal to the direction of applied force.