To actually have a serious discussion on the subject, I'm gonna run quickly through a long discussion I had a few years ago. The only electric motors powerful enough come from R/C electric planes.
Simply put... There are NO feasible car solutions (I don't care what "development" these guys are doing with capacitors & the like) for the power requirements to DRIVE an electric motor powerful enough.
R/C also gives us the only... Current realistic way of moving air (Tho NOT compressing it) as many 3-4-5" units are turning 35,000-45,000rpm.
Currently, the "rough" top end setups I know of are pushing around 2500-3000 watts around 80-120 amps per motor (Reportidly some using 4000-4500-5000 watts have ben done for short durations). We all know the old "It takes blah % power to drive blah supercharger". We also know that 749 watts = 1hp.
So... It aint gonna happen. Maybe 10-15 years from now... Not in the next decade will any of them become feasible.
You can even machine a little aluminum hub adapter and use two motors joined on their outputs with the fan in between them. So top that out at 6,000 watts. Still. It aint gonna happen!
Not to mention the flat out cost!?
You're looking at hundreds of dollars in motors, a hundred bucks for a fan of such size that can HANDLE the output.
A few hundred dollars in nimh, or even better Lipo batteries AND the charging equipment for them.
Atleast a hundred, or two for an ESC (Electronic Speed Controller) that can handle the current. (And there is no shortcut... You must have one)
You're looking for just a simple setup, around $1,000usd for one that would actually work.
Also... Don't get started thinking that even with the power, you could move air utilizing that power. Sure you can move it, but the name of the game is also compressing it! If you *could* move more air than the engine can injest, it's just going to go right back around the fan blades to some extent.
Then what happens when it's not working? It's weather vaning in the intake, cutting the cross section of it by more than half. Hello pressure, velocity, flow drops!
Lastly... Even if you could throw several thousand dollars at it... Don't think you can stack them in series one behind another like that dumb e-jet does. Every progressive ducted fan/turbine/anything that is set behind another works at only 15% efficiency. (115% of not enough is still not enough)
All that being said doing it this way... Could you *make* one for $1000 that would give actual horsepower? Oh yes. There is NO debating that one would not work. It's just down to three questions:
1) What does it cost
2) Does it have the raw power, rpm, and fan to work
3) Batteries
I told someone years ago. If that $30 worth of component E-ram can *actually* make a handful of horsepower, I could make 3-4x what anybody else is doing. Simply by using the *real* components of what they are trying to do.
The morals of this post:
No. Such devices that are currently being sold are not going to work in the least bit.
Yes. You could do something in a similar fashion and actually get a nice gain out of it.
Yes, the price/performance, and outright cost would be up the scale, but not as bad as some things that people do on a regular basis. I.E. headers on a Toyota v6. etc.
I hope everyone is a wee bit more informed as to what's going on & why the internet junk doesn't do anything. - Not because it *can't* do anything, but because everyone is just doing it wrong in the first place!
