Wow - Very Cool

[groovychk]

http://www.newscientisttech.com/article/mg19125681.400;jsessionid=NMGHKBGMCGMM

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Roger Shawyer has developed an engine with no moving parts that he believes can replace rockets and make trains, planes and automobiles obsolete. "The end of wings and wheels" is how he puts it. It's a bold claim. Read Shawyer’s theory paper here (pdf format).

Of course, any crackpot can rough out plans for a warp drive. What they never show you is evidence that it works. Shawyer is different. He has built a working prototype to test his ideas, and as a respected spacecraft engineer he has persuaded the British government to fund his work. Now organisations from other parts of the world, including the US air force and the Chinese government, are beating a path to his tiny company.

Comments

[xaminmo.livejournal.com]

Let's work with something about the mass of my car, since it's smallish and fairly efficient.

We'll ignore the normal drag (my car is about 120lbs of additional drag) and assume we're using carbon composite with teflon coating on an aerodynamically sound shape, which should give us some mass to play with in the design.

My car, including me in it, weighs about 3500 pounds. This is 1587.5 kilos. Conversion to composites, transparent alumina, skids vs wheels, and removal of the existing power train will give us probably about half of that to work with for our propulsion system. Money is no object in dreamland.

To overcome gravity, we need 9.8 newtons per kilogram (as in 9.8m/s/s). So, we're looking at 15557.5 newtons, just to counteract gravity, assuming the aparatus to generate electricity and thrust weigh no more than the normal power-train of this car.

According to the document referenced, it takes 1kW per 214mN. This means we need 72698.6 kW of energy to overcome gravity. To save from having to have huge conductors, we need to keep the amperage down, let's say around 100 amps.

There will be losses in power conversion, probably two step-up phases, but we'll assume 95% efficiency at both. Again, expensive, but not impossible.

This brings us to about 800 volts. We'll choose thin-film lithium polymer batteries, since anything else would be too heavy. They'd be rechargable about 30 times, and after that, they would need to be rebuilt, due to current limitations in the technology. Probably 300 pounds there.

I've been able to find references of magnetrons up to 50MW, so I'm sure 73MW would be feasible. It'd be heavy. A pulsed magnetron at 2MW including driver magnet is 46 pounds. I don't know what the duty cycle is for that, but we need constant force, no?

I found 1.5MW magnetron specs at 175LBs. I would expect larger ones to scale non-linearly. Let's say a 73MW one would weigh, what, 400 pounds?

We need to step up voltage to the 60kV range. Probably another 300 pounds for that.

So, it's probably doable, though it'd be really costly. Probably $100k for the magnetron alone, though its life span would be in decades. Power conversion would be good for a couple of decades, but the batteries would need pretty regular service, unless you're willing to go with a reactor, plutonium decay thermocouples, or or or.

This would be cost prohibitive for civilians, and very difficult for under-water where drag would be huge.

I could see this for use in space, where gravitational effects were much smaller and "wind" resistance much less.

[(Anonymous)]

Gravity, what is it?

www.newnrg.com

[kyrie1618.livejournal.com]

It seems to be an (improved?) version of a light drive... stick a flashlight out the back of a spaceship and light pressure drives you forward. Like a super-ion drive. Seems to me that a lightsail would work better, at least in the inner solar system.

[kyrie1618.livejournal.com]

Well, it looks like it works... but his explanation of *how* it works is gibberish. Also, I've read about "dangerous ideas" a few times in New Scientist and so far I haven't seen any of them work out. This one has at least passed experiment, so the next thing is for other people in other labs to repeat the experiment. Might turn out to be cool - but 88 millinewtons per kilowatt is only useful in space travel. Can they improve the thrust/power ratio?

The Heim Drive looked pretty promising to me. Futher discussion about it here: http://forum.physorg.com/index.php?showtopic=4385&st=0