Just an old habit, water will do the same, or better mercury in the outer space. Could be combined with a slingshot propulsion and so become a nice combination for Mars missions....Why hydrogen? Why not something less explosive?
Just an old habit, water will do the same, or better mercury in the outer space. Could be combined with a slingshot propulsion and so become a nice combination for Mars missions....Why hydrogen? Why not something less explosive?
Catastrophic spinning could be avoided by having two counterrotating flywheels in the same vacuum chamber, all but guaranteeing that if one goes, so will the other.I suppose, multi walled could mean, that the inner flywheel housing could rotate in the outer housing in case of a flywheel disintegration to prevent the vehicle from a catastrophic spinning.
Again, that could make the flywheel into a very useful explosive.the amount of energy released in case of a crash is much higher than a load of TNT!
^This. Manoeuvring would be problematic. Basic Newtonian physics.The amount of angular momentum should make vehicles based on them very "interesting"
Any gyroscopic effects would be cancelled out with the use of contrarotating flywheels.Ahem.
^This. Manoeuvring would be problematic. Basic Newtonian physics.
I think you already have examples of that with submunitions.And this sort of power density could make these flywheels into very effective explosives.
Again, that could make the flywheel into a very useful explosive.
Still, explosives have their uses in mining and excavation and obviously for military and ever since dynamite and TNT hit the scene well over a century ago, we have not seen a step change in energy density in that field, except for nuclear weapons, but that's a whole other storyExplosives are not useful in every applications, like e.g. cars...
Note, the amount of energy stored in such an hypothetical flywheel would be higher than everything which can be achieved with chemistry!
The most likely scenario for a flywheel failure would be from loss of vacuum, so the oxidation will happen within what's left of the housing.Since the flywheel is housed in a vacuum it cannot be oxidized in case of a disintegration until the housing is shredded to pieces, after this event, yes a mixture of fine carbon dust molten or even gaseous carbon will happily react with a atmosphere which messes up the situation even more....
Where there's a will, there's a way.They can also explode, but their energy content is just a fraction of that stored in the ideal carbon tube flywheel.
Its hard to imagine a housing which could contain a disintegrating flywheel, note the stored energy would be much higher than that of any chemical reaction! The Carbon would turn to Carbonsteam mixed with superfast shrapnel's, this will blast any housing which would fit into a vehicle.
Carbon nanotubes and carbon fibers are different things. Nanotubes don't need resins to join together, they readily bundleKeep in mind, no carbon fibre structure is made out of carbon fibres alone, you need a resin to keep it all together. When spinning several times with the speed of sound, it will become difficult to keep the resin attached, it is only bonded by adhesive forces to the fibres. If the outer layers of the resin start to fall off, the process of desintegration will start.
Since fibres can take load only in one direction, it is not so easy to built at flywheel out of them. You might make it as a ring structure, but than you have to integrate at least some magnets in it, which add weight but little additional strength. Or you might use spokets to attach the magnets on a smaller radius were the forces are less critical, but than you get a mix out of radial and tangential fibres which have to be connected somehow. The resulting structure will be less efficient than a theoretical perfect ring structure.
Can you keep 10 kg of TNT in a barrel by adding some magic adsorbing materials?
That's because nobody has managed to make large numbers of nanotubes of uniform length and quality.Probably no one has ever done a real life part out of Nanotubes... I guess, even the bundles can be considered as fibres and not as a rope.
That's because nobody has managed to make large numbers of nanotubes of uniform length and quality.
View attachment 779790
If carbon nanotubes are too unrealistic, how about diamonds? It's easy to imagine making a torus shaped diamond and progress is being made on making diamonds cheaper.
By the time we have EVs running on diamond flywheels, diamonds will have long ceased to be a novelty.I would like to see a rotating diamond in a glass housing in the engine bay![]()
I would like to see a rotating diamond in a glass housing in the engine bay
Most materials can only bear a fraction of the theoretical limitation (strength of the chemical bonding). Producing fibres enables to get closer to theoretical strength but loosing the ability to transfer forces in two of three directions. Monocrystal Diamonds could be an option, but we will have to wait until a 10 kg Diamond will become affordable..
For Sci-Fi, I would like to see how we enter space with a space elevator (made of Nanotubes) and enter a spacecraft driven by a flywheel with slingshot propulsion. This way, we could travel to Mars and back purely with mechanical energy.
None of these shapes are suitabel for a fibre only design. The bar shape e.g. on the very left, doesnt make sense without sheer forces. The shorter fibres are just underutilisiesed. It is also unclear, how the fibres will be attached to the shaft. Just arranging them to a bar and drawing a shaft going through the middle is no solution.View attachment 779954
Engineers in the 70s devised ways that "super flywheels" could be designed solely from fibers.
Magnetic bearings might workNone of these shapes are suitabel for a fibre only design. The bar shape e.g. on the very left, doesnt make sense without sheer forces. The shorter fibres are just underutilisiesed. It is also unclear, how the fibres will be attached to the shaft. Just arranging them to a bar and drawing a shaft going through the middle is no solution.
Not for attaching the fibres to the shaft...Magnetic bearings might work
Carbon nanotubes themselves can be made magneticNot for attaching the fibres to the shaft...
Perhaps this could be useful for absorbing the blast of a failed flywheel