Harvesting Precession Kinetic Energy

[Senax]

I was discussing with a colleague how one might extract the 3rd derivative precession kinetic energy from the action of the 360° full circle pendulum (FCP) and he came up with the following rough sketch.



If you have two FCPs following closely on one another they are wider apart near the nadir where the pendulums are travelling quickly and closer together near the zenith where the pendulums are travelling slowly.

If the bobs are connected by bellows then the gas inside the bellows will be compressed as the bobs approach the zenith and expanded as the bobs aproach the nadir.

A set of pendulums following one another at a set time interval will therefor provide an expansion/compression cycle.

Connecting bellows under compression with bellows under expansion will provide a flow of gas which can be used to drive a fan at the axle and step down the 3rd derivative precession kinetic energy (PKE) to 2nd derivative rotational kinetic energy (RKE).

Using gas pressure differences would seem to be rather impractical but one can achieve the same effect using mechanical links driving a cranked axle.

The leading pendulum will be attached to the axle and the following pendulum will be free. We can think of the leader as a stator since it is static in relation to the axle and the follower as an oscillating rotor.

One only needs to generate enough energy to get the pendulum over top dead centre and then the cycle will repeat.

The relatively small back and forth movement between the stator and rotor puts me in mind of the relatively small movement of the displacer in my model Stirling Engine. This in turn suggests the the action could be harnessed mechanically by means of a suitable linkage involving a long con-rod and cranked axle.

[Senax]

Replying to enable quote.

[sleepy]

It will take much more energy to drive the pendulums than the compression/expansion will provide. Not to mention the timing nightmare as the pendula constantly change speed due to the force of the gas and the bellows.Thanks for sharing.Nice idea for being off the cuff so quickly.

[Senax]

The energy is there since the centre of mass for the circuit of a 360° pendulum is higher than the centre of rotation. In the limit it is one radius higher. This is clear from simple inspection of a series of pendulums dropped at one second intervals.

The energy is of course in the form of precession kinetic energy.

The problem is not theoretical but practical. In particular, how to feed back enough of that energy to keep the cycle going.

[AB Hammer]

Greetings Senax and welcome to the forum.

You might want to look through some albums and see the ideas of us who have posted. There when thinking you can find where others thoughts in the drawings.

Here is a couple of ones I cam up with, that has some similarities of what you are trying.

http://www.besslerwheel.com/forum/downl ... er=user_id

http://www.besslerwheel.com/forum/downl ... er=user_id

The biggest problems is the time it takes to do an action and we tend to do a lot of trade off and watch them sit there.


Keep up the thinking for the mind is a true wilderness.

[justsomeone]

Abhammer, senax is Grimmer. He is quite familiar with the forum. 😊

[Senax]

Abhammer, senax is Grimmer. He is quite familiar with the forum. 😊

There's no Grimmer on the list of members.

[justsomeone]

Sorry Frank for the extra " M ".
Enjoy your day.

[Senax]

The energy is there since the centre of mass for the circuit of a 360° pendulum is higher than the centre of rotation. In the limit it is one radius higher. This is clear from simple inspection of a series of pendulums dropped at one second intervals.

The energy is of course in the form of precession kinetic energy.

The problem is not theoretical but practical. In particular, how to feed back enough of that energy to keep the cycle going.

Count them for yourself.

Eight below the centre. Sixteen above.

[sleepy]

There are two problems with this concept right off the bat.
1. Pendulums gain weight at the bottom of their swing.That extra downward pull must be accounted for.
2. You are talking about free-swinging pendula. Once you attach them to something at any point in their swing,all of this info must be recalculated.

[Senax]

...
1. Pendulums gain weight ...

"Some standard textbooks[4] define weight as a vector quantity, the gravitational force acting on the object. Others[5][6] define weight as a scalar quantity, the magnitude of the gravitational force. Others[7] define it as the magnitude of the reaction force exerted on a body by mechanisms that keep it in place: the weight is the quantity that is measured by, for example, a spring scale. Thus, in a state of free fall, the weight would be zero. In this sense of weight, terrestrial objects can be weightless: ignoring air resistance, the famous apple falling from the tree, on its way to meet the ground near Isaac Newton, would be weightless."

[sleepy]

At the very lowest point in the pendulums swing.where it stops moving downward and begins its rise,it exerts extra force on whatever it is tethered to. Just grab a rope,tie it to a 20 lb weight.and swing it in a vertical circle and you will clearly and undeniably witness the extra force at the bottom of the swing.Don't get hurt though! Do not let the weight come in contact with any living thing while the weight is in motion.

[Senax]

The energy is there since the centre of mass for the circuit of a 360° pendulum is higher than the centre of rotation. In the limit it is one radius higher. This is clear from simple inspection of a series of pendulums dropped at one second intervals.

The energy is of course in the form of precession kinetic energy.

The problem is not theoretical but practical. In particular, how to feed back enough of that energy to keep the cycle going.

I've realised it isn't necessary for the pendulums to go "over the top". In effect the apogee, 350° for example, the highest point of the swing, is a kind of top. The pendulum comes to a halt at the 350° "top", just as it would if it was going over the 360° top.

Of course it changes from clockwise to counter clockwise direction as it goes back down the other side but that's no problem. Feeding energy into a main wheel, in effect a fly wheel, doesn't have to be continuous - and changes in direction can be accommodated by appropriate mechanical linkages.

I've realised something else as well. Using up the difference in position between a pair of pendulums, the 3rd derivative, does not reduce the 2nd derivative energy at all. The vertical component of movement of one of the pair of bobs is compensated by the opposite vertical component of the other bob.

In other words the Rotational Kinetic Energy and the Precessional Kinetic Energy are independent variables.

Thus a pair of pendulums can be see as a analytical energy "chromatography" tool to separate out the gravitational potential energy from the stress potential energy; the 2nd derivative from the 3rd derivative.

[Senax]

Here is a GIF of two pendulums slightly out of phase.



It can be seen that the distance between them expands from 1 o'clock to 6 o'clock and contracts from 6 o'clock to 11 o'clock.

This expansion and contraction cycle is down to 3rd derivative precession energy which can be harvested mechanically or electrically in an analogous way to that of a Stirling engine.

https://www.youtube.com/watch?v=gQb2sN6UWkA

Indeed, it may well be that Bessler has already done this since his drawings show two pendulums out of phase by a much larger angle than the two pendulums shown above and driving cranks connected to a flywheel.

I don't think this is the whole story though.

I suspect that the internal mechanism comprises a number of Milkovic devices with a second pendulum replacing the weight. Since these devices will be rotating about the centre the 4th derivative, Snap energy, will also be involved.

Finding the correct parameters for the external pendulums should give sufficient insight for building an equivalent Bessler wheel.

https://www.youtube.com/watch?v=gQb2sN6UWkA

[ME]

Your pendulum does not have a constant energy input as the Stirling...

3rd, 4th, 5th.. derivative - Look into Taylor series, perhaps you could identify it as a Sine, or Cosine function.