Using flywheels to increase FE

[Christ]

What's cool about that, is the entire assembly could essentially fit in a small air tank... so the vacuum chamber and the reinforced enclosure could be the same thing. The only thing from that point would be extracting said energy, and storing it to begin with.. while keeping the container under vacuum.

I'm pretty sure a Vacuum pump could pull enough air out of the assembly to create a vacuum, without it being completely sealed, but would it be worth the effort?

Also, with a Vacuum pump removing air from the assembly, and air coming in from other areas, would the airflow profile in the container create a negative effect on the bearings? i.e. wobbling, etc... since the bearings are obviously magnetic, and the flywheel would be floating.

[Bicycle Bob]

Vacuum is very thin stuff, but that makes leaks easy to find. The effect of any stray air would be almost pure friction. However, it is expensive to pump vacuum, so a seal is normally maintained. The safety enclosure would double very well as a vacuum tank. The best bet for getting the power in and out seems to be spinning a permanent magnet and using high-frequency electronic commutation to a ring stator. In the lab, efficiency can beat a battery, but I'll wait until I can buy the whole system off the shelf. The effort has not been abandoned.

[Christ]

For educational purposes:

What you're saying is to seal the flywheel in there, attaching magnets to the flywheel itself, and then adding coils to the OUTSIDE of the casing to pickup the magnetic fields and create electrical current?

That's what I got from it.

What it led me to think:

Why not place the entire assembly inside the casing, with the flywheel(s) floating, and the coils attached to the inner walls of the casing?

Given the oblong shape of most air cylinders, would it be more beneficial to use more than one flywheel, or to create a single one that would occupy as much of the usable space as could be occupied?

The current could be carried out by wires, obviously, and a seal could still be maintained, under light vacuum. How much vacuum would be necessary/ideal?

Also, how would one impart energy TO the flywheels for storage?

[Bicycle Bob]

Cylinders are easily produced to any proportions. I'd keep an eye on the space available for installations, but try for a rig with two counter-rotating flywheels and close to spherical shape overall as best for minimum weight.

[Christ]

Well, I can understand that part, but as far as the shape adjustment, I actually meant the shape/size of the flywheel that occupies the inside of the casing... The casing having already been chosen for a specific area to fill inside the car.

So say you have a cylinder already, with a rough dimension of 20" long, 10" diameter (circle). Assuming 2 flywheels, counter-rotational, one would think that 2 8" wide discs would be the best occupation of space, correct?

(That sizing leaves around .7" on the outside edges of the discs, and .7" between them, to account for any "wobbling" caused by bumps/jumps in the car.)

I'm not entirely sure this is something I could actually build at home. I might give it a shot though, even if I can't build a working example, I might at least model it.

[aerohead]

Originally Posted by jamesqf

Not flipping end over end, no. But spinning in circles 'cause the idiot driving didn't realize that 4WD doesn't improve your steering control, yes, several times. And what else is new?

Anyway, you're missing the point. You've made up some superficially plausible thing that could go wrong, sort of like the theory that hybrids were going to electrocute rescuers after accidents, or that magnetic fields from electric cars would cause cancer, and try to use that as a justification for not developing what might be a useful technology. The point is that if you bother to actually think about what's involved, instead of running in circles claiming that the sky is falling, you soon see that your superficially plausible threat is nothing of the sort.

Start with your basic thesis: that the bearings of a flywheel might somehow seize up, and suddenly transfer the momentum of the flywheel to the whole car, causing it to tumble end-over-end down the highway. The first problem is that a sensible energy-storage flywheel design uses magnetic bearings, spinning in a vacuum. There's no physical contact, and thus nothing to seize. Second, the flywheels are built of things like carbon fiber, so when subject to a sudden severe stress of that sort, they would harmlessly disintegrate into tiny pieces.

You know, you can actually look up these things on the web. People have built these sorts of flywheels, and destroyed some of them in testing. It's something called engineering, you know.

I'm actually very interested in the whole concept.I'm playing the Devil's advocate simply out of safety regards.I've seen inside of Chrysler a little, and they've done some very clever things over the decades.I figured maybe,if they couldn't pull it off,and were afraid of it,then it was worth mention.-------------------- I think the reason we've ended up with the electric hybrid,is that it accomplishes much of what the flywheel might,and with very high efficiencies for motor/generators,inverters,batteries,'n such,they can recover decent levels of braking energy,store it,and then re-deliver it to the traction motor with "seamless" operation.--------------- I've got some articles on the super-flywheels,with the magnetic-bearings,operating in a vacuum.For a stationary unit,the challenges of impact-loading on the bearings would be cut to zero.Pot-holes might be a challenge,as "jerk" loads are the most severe for engineering applications.--------------------------- I like BicycleBob's idea of the rotating magnet and faraday-coil export of power.My oldest brother would caution,that because of the geometric relationship between Gauss at the rotor,and losses at a distance from it,that extremely tight tolerances would have to exist the rotor(flywheel) and inside of the vaccum vessel,and the coil would probably have to be embedded in the vessel itself,to allow close proximity to the rotor magnetic flux.-------------------- All my uncles were involved in aerospace.One in particular,with North American Rockwell,had explained to me that they manufactured some of their products with "spin-welding" technology,where two structures are allowed to touch while one spins,and the friction generated at the interface is enough to produce a permanent weld.----------------- This accounts for my reservations about what might happen should the vacuum fail and windage effects overcome the magnetic separation,causing the bearings to weld.If the rotor does not contact the inner surface of it's container and self-destruct,all the energy will be transferred out via the shaft perhes.I think Chrysler may have experienced this.----------------------------------- And evidently,with their Patriot-Car program,the flywheels can store kinetic-energy levels great enough,that should the rotor weld-up,whatever the supporting structure is that contains the flywheel,it is going to go for quite a ride,depending on axis of rotation and CG of the vehicle.---------------- I'd love to see 'em make it work

[jamesqf]

Originally Posted by aerohead

I've seen inside of Chrysler a little, and they've done some very clever things over the decades.I figured maybe,if they couldn't pull it off,and were afraid of it,then it was worth mention.

I'll allow that that's possible, but I don't think it's likely. After all, we have a history of 30-40 years of clever fuel-saving ideas coming out of the Big 3, all of which were abandoned in favor of the "build 'em bigger, and increase the advertising budget" theory. Hell, even the not-so-clever ideas like building smaller, lighter cars to compete with the imports (or putting your employees' retirement funds aside as you go, instead of using them to inflate profits) seem to have fallen by the wayside.

I've no doubt that there's a lot of engineering development still needed on flywheel power systems before they're ready for cars. But stationary systems would be a place to start: suppose every house with solar panels also had a flywheel system that could store a day's worth of energy. Such a system would be way more efficient than battery storage (which isn't all that efficient), and all of a sudden solar becomes a lot more practical. You no longer need to feed your excess solar generation to the grid, only to have to buy it back after dark. Add some intelligence to the system, and you can even use it for some load-balancing, making it possible to put more intermittent solar/wind generation on the grid.

[Christ]

I saw on the green channel a thing about hydro power that can be created without a nearby stream...

It's a high-speed medium output generator that uses the force from water, but the system that uses it is the most unique I've seen to date:

One group of hunters powers their cabin with it: a 200 gallon (I think) under ground "catch tank" on at the bottom of a hill, with ~200 feet of piping running to the generator house, all of which is small gauge drainage pipe, perforated.

Water goes from the water table in the ground into the pipe, runs down the hill, powers the generator, then runs into the bulk tank (which is more like a septic tank, and is able to disperse excess water without flooding, through a leech-field effect) for bulk-water use, such as cooking and showering, and could be boiled to extract drinking water.

A system like this, which doesn't provide a large amount of power, could definitely benefit from a more efficient storage solution than batteries, since you're not using power while you're sleeping, or out on the hunt.

Obviously, this could be employed for more than a hunting cabin as well.

I love the "Green" Channel.