Perpetual movement Power Plant?

[McPerth]

I know this breaks Newtonian physics. Just playing a little with numbers here, using MT design system (we all know quite flawed about power and efficiency), and assuming earth gravity and vacuum (to avoid friction and Archimedes Law derived lift):

If you put a low power TL12 grav plate for 1 ton thrust to a weight for a total of 900 kg you have 0.11 g (1.08 m/s2 ) acceleration to lift it, needing 4.3” to lift it 20 m. At 20 m the grav plate is turned of, gravity stopping it in about 0.4”, having reached a height of 0.29 m more.

As to use this grav plate you need 0.02 Mw, total energy use for those 4.3” will be 86000 Joules.

By lifting those 900 kg to 20.29 m height, its potential energy will raise 900 kg x 20.29 m x 9.8 m/s2 = 178958 Joules. If you then leave it to fall to produce energy, if your conversion efficiency is 50%, you obtain 88200 Joules of energy, ending with a net 1279 Joules of energy win. As fall will take about 1.44”, total time for the cycle will be about 6.2”, so giving a net win of about 200 Watts (and raising if efficiency is over 50%). See also that lifting it to greater heights will improve efficiency too.

And at TL13, power needed for this same 1 ton of lift is halved to 0.01 Mw, so your energy win would be 44279 Joules, and net power production of about 7141 Watts at 50% efficiency.

Could this way a power plant based on this perpetual movement be built, by using several such items in parallel and batteries for the lift time power?

 

[Dragoner]

Yes, just use a reciprocating assembly such as in a IC engine.

 

[sabredog]

There will still be friction from the interaction of the plates and from whatever this thing is connected to to generate the power. Won't that also cause a gradually increasing loss of momentum? I'm no physics major but eventually the diminishing return will catch up the output. Won't it?

 

[Dragoner]

It's really just raising the efficiency bar, there is entropy in any system, so eventually it would fail. Bearings though could be maglev. IMO what would kill it would be heat cycles and resistance in the circuits, but it would take a while.

A+ for creative use of grav.

 

[HG_B]

I'm no physics major but eventually the diminishing return will catch up the output. Won't it?

Not with the numbers in the OP. THAT is the problem.

 

[McPerth]

There will still be friction from the interaction of the plates and from whatever this thing is connected to to generate the power. Won't that also cause a gradually increasing loss of momentum? I'm no physics major but eventually the diminishing return will catch up the output. Won't it?

That's why I assumed an eficiency of 50%. As neither I am physics expert (nor engineer), I cannot tell if 50% efficiency is an adequate assumption.

A+ for creative use of grav.

Not with the numbers in the OP. THAT is the problem.

TY for you A+, Dragoner, but mostly I tried (as HG_B points) to ask people if they believe this perpetual movement of first kind (so a breach of the first Thermodynamics Law) is seen as acceptable in MT universe or is another flaw in the game designers efficiency values (this time too much efficient, as produces lots more of energy that it uses)

 

[aramis]

Som efficiencies for reference:
Nat Gas peaks at about 42%.
Coal, Nuke at about 32%
Petroleum at 31%

using the numbers from http://www.eia.gov/tools/faqs/faq.cfm?id=107&t=3

50% would be impressive.

 

[rancke]

TY for you A+, Dragoner, but mostly I tried (as HG_B points) to ask people if they believe this perpetual movement of first kind (so a breach of the first Thermodynamics Law) is seen as acceptable in MT universe or is another flaw in the game designers efficiency values (this time too much efficient, as produces lots more of energy that it uses)

The flaw is the assumption that game rules are a 100% accurate reflection of the physics of a universe that resembles our own to a remarkable degree.

As far as I am concerned, if a rule allows for what appears to be the creation of energy, then it's wrong. Though that doesn't mean it can't be a rule that works for whatever limited application it is supposed to be applied to. Or that some kind of science-fictiony handwave can't be used to cover up the impossibilities ("The extra energy comes from another dimension!")


Hans

 

[Timerover51]

Although from another game system, also by GDW, you might want to take a look at the power plant in Canal Priests of Mars, from the Space; 1889 milieu.

 

[McPerth]

Although from another game system, also by GDW, you might want to take a look at the power plant in Canal Priests of Mars, from the Space; 1889 milieu.

Space 1889 does asume quite different physics from Traveller, but you're right, the liftwood wheel in Canal Priest from Mars had something to do with my idea about this power plant.

 

[McPerth]

Som efficiencies for reference:
Nat Gas peaks at about 42%.
Coal, Nuke at about 32%
Petroleum at 31%

using the numbers from http://www.eia.gov/tools/faqs/faq.cfm?id=107&t=3

50% would be impressive.

Aside from the improvements TL might bring (anyone's guess), see that all those power plants you say waste lots of energy in heat and expanding gases, waste that will not be in this kind of PP.

And even if efficiency was lower, just making the columns higher will raise the power given while not so raising its needs (e.g., to raise it to 40 meters instead of 20, you doubled the potential energy while only spending 6.08": less than 1.5 multiplier for the time (and so the energy) needed for twice its return).

In the same case told before, you'd spend 121600 joules for a return of about 397000 joules. Even at 30% efficiency is would be worth of it (a net return of about 10700 joules over about 10" span, so about 1 kW assuming 30% efficiency).

And all those calculations are for a TL 12 plant, at TL 13, with half of power needed, the return would be over 70000 joules, each column over less than 10" span, so above 7 kW power...

I guess to make it as a wheel, as the 1889 power plant Timerover told about would increase efficiency even more, but it would be more difficult to calculate (over my knowledge, I'm afraid)

 

[Timerover51]

While it is not covering very high Tech Level material, this might be of interest to you, as it is a publication by the US Smithsonian Institute which includes perpetual motion devices. As a US government publication, it is in the public domain. It is located here on Project Gutenberg.

http://www.gutenberg.org/files/30001/30001-h/30001-h.htm

Title: On the Origin of Clockwork, Perpetual Motion Devices, and the Compass