In reply to Michel Jullian's message of Mon, 26 Feb 2007 09:55:41 +0100: Hi, [snip] >Not sure what you mean Robin, drawing welcome, I suspect it resembles a NASA >design where the wire was replaced by a sharp edge. I don't see how the thrust >could exceed the rate of change of momentum transmitted from the ions to the >air i*d/mu though, as this experimentally verified formula already assumes >zero air resistance of the lifter structure. Also beware that charges >deposited on insulators interact with the discharge!
My suggestion was more intuitive than scientific. I see an analogy between the thrust from a lifter and the exhaust of a jet engine. The current lifters basically hover on their exhaust (i.e. the exhaust is pointed down to generate upward thrust). By causing the air to flow down over the top surface of the Frisbee shaped lifter and up underneath the lifter, the whole body becomes a sort of airfoil, with a low pressure region above it and a higher pressure region below it. The difference in air pressure is multiplied by the entire area of the craft (Pi x r^2) to calculate the lifting force. By analogy we are adding wings to an aircraft, and pointing the exhaust rearward. To see what a difference this makes, consider the British Harrier fighter/bombers (http://www.harrier.org.uk/). > >(BTW it's Coanda, not Coander) Thanks. [snip] Regards, Robin van Spaandonk http://users.bigpond.net.au/rvanspaa/ Competition (capitalism) provides the motivation, Cooperation (communism) provides the means.
