In reply to thomas malloy's message of Thu, 30 Dec 2004 02:31:39 -0600: Hi, [snip] >>3 lbs per horsepower, using every dirty-trick in the book for enhancing >>Lifter efficiency. That includes boosting ion-wind, specific field-shaping, >>reversing the charge-polarity (power-supply runs negative), etc...
As I said about a year ago, better than a helicopter, but not as good as conventional fixed wing aircraft. However, as a helicopter/dirigible replacement it might be interesting, particularly when powered by a radioisotope, which naturally lends itself to high voltage low current applications. Even more so, if the decay rate can be controlled. Furthermore, lack of moving parts makes it possible to construct light weight devices capable of lifting very large loads, especially when using a lightweight radioisotope power source. >> >>There's no question that you could build an ion-wind aircraft, but it would >>be expensive, and I am looking at big-game hunting on some of the other >>ideas like gravity beams :o) >> >>Other than that, only changing the air is going to make a difference, and >>that tends to undermine any possible space applications. True, AFAIK. [snip] >>pounds of lift for a horse power, is that correct? I also found your >>comments on the observed lift being too large by several orders of >>magitude to be produced by the ion wind insightful. Not really. The ion wind calculation is based upon the velocity of ions in a vacuum, but the craft isn't operating in a vacuum. When operating in air, the ions encounter resistance, and drag air molecules along with them, which increases the effective mass of the ions many fold. This results in a much larger momentum transfer which explains the lift. This effect is maximised by increasing the air resistance, i.e. by making the current path as long as possible. Additional lift might be obtained by making use of the Coanda effect over a curved hull (i.e. flying saucer shaped because the air will flow in all directions, from top to bottom) see e.g. http://jnaudin.free.fr/html/repcotst.htm , except of course that the hull would need to be an insulator, not a conductor. [snip] Regards, Robin van Spaandonk All SPAM goes in the trash unread.
