Could ME thrusters be used to produce torque?

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ltgbrown
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Could ME thrusters be used to produce torque?

Post by ltgbrown »

I was mowing the lawn yesterday and started wondering what would be more transformational; polywell fusion or M-E thrusters? As I pushed my two cylce gas powered mower along, I thought about how things would be different in my day to day life if either were prevalent throughout society. Until we get a better energy storage device (better batteries, or hydrogen fuel cells (and hydrogen storage), or capicators, etc), polywell fusion won't really affect my day to day life until at least 20 or 30 years when it becomes so prevalent, that the cost of energy begins to drop to almost insignificance. In otherwords, I will still be mowing my lawn with a gas powered mower (and trimmer!).

So, then I thought about M-E thrusters. It will definately change things (more so than Polywell fusion I think), but will it change my day to day life, i.e mowing my lawn. My first reaction was no, because while the M-E thruster could move my mower across the ground (easier that rolling on the wheels), the blade still needs to rotate to cut the grass. Then I thought, just put two M-E thrusters on a beam that is supported at the center of its legnth and able to rotate about that point. That would definately produce torque, but would it be any more efficient at converting electrical energy into torque than current methods?

Over to others to calculate (Paul??) the answer to that question. Oh by the way, wouldn't the centripetal accelaration of rotating around the center point add some efficiency to the M-E thruster?
Famous last words, "Hey, watch this!"

IntLibber
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Re: Could ME thrusters be used to produce torque?

Post by IntLibber »

ltgbrown wrote:I was mowing the lawn yesterday and started wondering what would be more transformational; polywell fusion or M-E thrusters? As I pushed my two cylce gas powered mower along, I thought about how things would be different in my day to day life if either were prevalent throughout society. Until we get a better energy storage device (better batteries, or hydrogen fuel cells (and hydrogen storage), or capicators, etc), polywell fusion won't really affect my day to day life until at least 20 or 30 years when it becomes so prevalent, that the cost of energy begins to drop to almost insignificance. In otherwords, I will still be mowing my lawn with a gas powered mower (and trimmer!).

So, then I thought about M-E thrusters. It will definately change things (more so than Polywell fusion I think), but will it change my day to day life, i.e mowing my lawn. My first reaction was no, because while the M-E thruster could move my mower across the ground (easier that rolling on the wheels), the blade still needs to rotate to cut the grass. Then I thought, just put two M-E thrusters on a beam that is supported at the center of its legnth and able to rotate about that point. That would definately produce torque, but would it be any more efficient at converting electrical energy into torque than current methods?

Over to others to calculate (Paul??) the answer to that question. Oh by the way, wouldn't the centripetal accelaration of rotating around the center point add some efficiency to the M-E thruster?
Actually, some folks have theorized that you could use M-E thrusters when they reach 1 N/W efficiency, to power a generator to produce net power, however others see this possibility more as a demonstration that reaching these levels of efficiency will not be possible due to the potential for serious conservation violation.

In the mean time, I'd be happy to have them at 0.01 N/W efficiency, that alone would transform everything to do with transportation, and our whole society would change. Living on the moon you wouldn't have a lawn to need mowing.... lol.

kurt9
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Post by kurt9 »

Torque is necessary for ground transportation (cars, trains, etc.) as well as ships. If successful, MLT will be more revolutionary than polywell. If you can generate torque with this device, you're talking about an all electric transportation system.

Polywell is definitely desirable. But if we don't get it or any other fusion, there are new fission technologies waiting in the wings like LFTR's or IFR's. Also any of the D-T fusion systems, if they cannot generate power const competitively, can certainly be used for fusion/fission hybrid power plants. I think this the likely outcome IF we do not get B-H fusion.

BTW, I will have more on the new dielectric material (polymer/metal composite) early next year. Its under development right now. They are developing it for embedded power applications for MEMS devices.

93143
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Re: Could ME thrusters be used to produce torque?

Post by 93143 »

IntLibber wrote: Actually, some folks have theorized that you could use M-E thrusters when they reach 1 N/W efficiency, to power a generator to produce net power, however others see this possibility more as a demonstration that reaching these levels of efficiency will not be possible due to the potential for serious conservation violation.
Seeing as how someone else brought it up (heh heh):

Actually, in theory, given a sufficiently large flywheel at a sufficiently high speed, you could generate net power with much lower thrust efficiencies. A flywheel with a 5 m radius, rotating at 3000 rpm, could generate net power (assuming negligible losses, which is probably impossible) using the Mach-2MHz test article, assuming the reported data is correct.

Conservation of energy is not the issue. The energy would be harvested from the distant universe, just as in the linear acceleration of a spacecraft (the onboard stored energy in the batteries doesn't come close to the final kinetic energy of a Mach-effect-powered orbital launch vehicle; more discussion here).

[There might be an issue with entropy, but I haven't done the math and no one else seems concerned, so I'll shut up about it. Besides, wouldn't it be awesome if it worked and THEN someone proved it was a PMM of the second kind?]

It is, however, decidedly possible that even if the Mach-effect devices work, Polywell will end up having substantially higher power density than a Mach-effect spinner - at least the multi-GW space reactors, and possibly the smaller naval reactors if 1 N/W turns out to be too optimistic and/or the thrust-to-weight ratio is too low (the power output of these things can easily be limited by material strength). So there may still be a few applications left for Polywell...
kurt9 wrote:Torque is necessary for ground transportation (cars, trains, etc.) as well as ships.
Not really. If the thrust efficiency gets higher than 1/v, where v is the speed you want to go, it's more efficient to just use a Mach-effect thruster directly, rather than wasting energy pushing the Earth backwards. For reference, a car at highway speed would save energy doing this if the thrust efficiency were about 0.04 N/W or better. For a thrust efficiency of 1 N/W, break-even is 3.6 km/h (2.24 mph), neglecting drivetrain losses. This goes even more strongly for ships, because they actually exhaust a medium backwards at a finite additional speed (with viscous and swirl losses) instead of directly pushing on a very massive stationary object.

...

Lawn mowers, however, DO require torque. For a one-foot-wide spinner at 3650 rpm, the gain is about 58 W/N, so a thrust efficiency of 0.02 N/W would make this arrangement more efficient than a perfect, lossless electric motor, and a thrust efficiency of 0.035 N/W would make it self-powering (barely - you'd probably want some wiggle room for a real-life device, and almost certainly surge caps, considering what lawn mowers go through)...

ltgbrown
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Post by ltgbrown »

a thrust efficiency of 0.035 N/W would make it self-powering
some folks have theorized that you could use M-E thrusters when they reach 1 N/W efficiency, to power a generator to produce net power
Net Power? Uh, I don't understand. Help! :?
Famous last words, "Hey, watch this!"

93143
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Post by 93143 »

ltgbrown wrote:Net Power? Uh, I don't understand. Help! :?
Power is force times velocity. Or torque times angular velocity.

Take the lawn mower. Rotational speed = 3650 rpm = 382 rad/s. Power = 4 hp = 2984 W. Radius of the spinner I described = 0.1523 m. Torque required for that power output: 2984/382 = 7.807 N.m (5.758 ft.lb). Thrust required at that radius to produce that torque: 7.807/0.1523 = 51.26 N.

Power required to produce that thrust, at 0.035 N/W: 1465 W. So in this case you only use half as much power as you would have had to if you had used an electric motor. Or, to put it another way, you get 4 hp output for 2 hp input; ie: 2 hp net.

Put in 3000 W, and you get 105 N, for a torque of 16 N.m and a power output of 6112 W. Siphon off half that with an alternator and pump it back into the thrusters, and you've built a 4 hp lawn mower that obtains its power by tapping into the energy of the entire cosmos...

chrismb
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Post by chrismb »

A clear proof that M-E thrusters are bogus, then.

93143
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Post by 93143 »

chrismb wrote:A clear proof that M-E thrusters are bogus, then.
How so? Energy is conserved. Have you got a different argument?

chrismb
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Post by chrismb »

93143 wrote:
chrismb wrote:A clear proof that M-E thrusters are bogus, then.
How so? Energy is conserved. Have you got a different argument?
Are you not saying that energy isn't converved? (If it goes up?)

A different argument? Not sure what you're saying, I guess the 'different argument' here is that M-E thrusters are a totally daft idiotic creation of dim-witted unfounded understanding and mis-information in the crazy-lunatic class of blithering nut-case nonsensical fruit-cake fantasies, deserving only of ridicule.

..maybe I overstated that..

...nah!....

Betruger
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Post by Betruger »

chrismb wrote:Are you not saying that energy isn't converved? (If it goes up?)
93143 wrote:that obtains its power by tapping into the energy of the entire cosmos

93143
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Post by 93143 »

chrismb wrote:Are you not saying that energy isn't converved?
That is correct. I am not.
93143 wrote:Conservation of energy is not the issue. The energy would be harvested from the distant universe, just as in the linear acceleration of a spacecraft (the onboard stored energy in the batteries doesn't come close to the final kinetic energy of a Mach-effect-powered orbital launch vehicle; more discussion here).
You've started insulting people now, without having made even a cursory attempt to understand how the M-E thruster is supposed to work (momentum exchange with all matter in the universe in accordance with gravinertial field theory). Net power in this case is local. Energy decreases elsewhere to supply it.

I'm not saying Mach effect thrusters will definitely work (I consider the experiments to date inconclusive, though promising). But on paper they do satisfy conservation of momentum and energy, so if they don't work it will be for no such obvious reason. Sciama's successful expression of Mach's principle in terms of GRT may have been a misguided red herring, but if it wasn't, what I've described above should be possible, at least in principle.

chrismb
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Post by chrismb »

93143 wrote: You've started insulting people now
Who, me?

Who have I insulted? I've insulted a 'creation', this being the 'subject' of my statement. If someone infers that the idea they hold so dear to them is shot down by me, I'm not shooting them down, only their love for the idea.

Energy cannot be preserved in the way that you claim, because 'the rest of the universe' is a 'null' inertial frame and you cannot give back to that universe the same energy, you have to give it back to a specific inertial frame that the energy transfer occurs in. KE=mc^2 - m[o]c^2, so you have to have a frame in which the m[o] is referenced.

93143
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Post by 93143 »

chrismb wrote:Energy cannot be preserved in the way that you claim, because 'the rest of the universe' is a 'null' inertial frame and you cannot give back to that universe the same energy, you have to give it back to a specific inertial frame that the energy transfer occurs in. KE=mc^2 - m[o]c^2, so you have to have a frame in which the m[o] is referenced.
Pick a frame, then. Any one will do.

Better yet, go read my post on nasaspaceflight.com, that I've linked twice now. It's four or five posts down the linked page.
Who have I insulted? I've insulted a 'creation', this being the 'subject' of my statement. If someone infers that the idea they hold so dear to them is shot down by me, I'm not shooting them down, only their love for the idea.
I noticed you were very careful to avoid technical ad hominem while still being as insulting as possible. I'm not really offended (it's not my idea; I'm just a cautious fan), but I do think that the amount of time it must have spent you to compose that string of choice words could have been better spent trying to understand the concept you were ridiculing.
Last edited by 93143 on Thu Oct 01, 2009 9:05 pm, edited 1 time in total.

MSimon
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Post by MSimon »

chrismb wrote:
93143 wrote: You've started insulting people now
Who, me?

Who have I insulted? I've insulted a 'creation', this being the 'subject' of my statement. If someone infers that the idea they hold so dear to them is shot down by me, I'm not shooting them down, only their love for the idea.

Energy cannot be preserved in the way that you claim, because 'the rest of the universe' is a 'null' inertial frame and you cannot give back to that universe the same energy, you have to give it back to a specific inertial frame that the energy transfer occurs in. KE=mc^2 - m[o]c^2, so you have to have a frame in which the m[o] is referenced.
As I understand it ME theory says there is no null inertial frame. Just as there are no "fixed stars" . Both are convenient fictions. Well at least one is. For the other the experiments so far are inconclusive.

If m is dependent on the rest of the universe you have left out some important terms in your simplified equations.

Now it is more that possible that ME is wrong. But right now we don't know that. So what we do is ask "if it is true what would we expect to see?" Then design the experiment accordingly.
Engineering is the art of making what you want from what you can get at a profit.

Betruger
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Post by Betruger »

93143 wrote: I noticed you were very careful to avoid technical ad hominem while still being as insulting as possible. I'm not really offended (it's not my idea; I'm just a cautious fan), but I do think that the amount of time it must have spent you to compose that string of choice words could have been better spent trying to understand the concept you were ridiculing.
That's not "insulting". It's only a difference in vernacular; a mere intercultural misunderstanding. :wink:

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