Yes I mean drag, but there may be other aerodynamic forces to consider. Also I don't think the profile is aerodynamic because the boundary is not crisp like a fuselage. Does gf mean g-force? If so that a percentage of the acceleration due to gravity or a force as in force = ma ?
The fact that a certain current coincided with lift off does not necessarily provide a comprehensive explanation of what makes it go. For example, the current drawn by spark plug does not account for the motion of the blade on a lawn mower. Anyway, if an accelerometer were mounted on a lifter the actual dynamic forces involved could be estimated more accurately. Unfortunately I can't view the video on my antiquated iMac. Harry Michel Jullian wrote: > I agree that the lifter's ion [induced] wind adds to the aerodynamic drag > during ascent (I think that's what you're saying, note you could say the same > of a helicopter's propeller induced wind) > > Anyway in the case of the lifter this wind is relatively slow (of the order of > 1 m/s, about 100 times slower than the entraining ions which are not very good > "paddles" and not very numerous), and the profile is usually quite > aerodynamic, so the corresponding drag is quite small. This means that in > practice the thrust needed for takeoff isn't much more than the device's > weight. > > Example (Blazelabs 100g payload lifter): total weight of lifter + payload = > 187gf, let's see what current is needed for a thrust of 187gf. The gap being > 92mm, by applying the EHD thrust formula: > > thrust in gf = 0.5*i*d with i in mA and d in mm > > we find that we need a current of 4.1mA (187/(0.5*92)). In practice Xavier > found that the lifter almost took off at 4.2mA, and definitely flew and tensed > its tethers at 4.4mA: > > http://www.blazelabs.com/e-exp14.asp (do watch the video) > > Michel > > ----- Original Message ----- > From: "Harry Veeder" <[EMAIL PROTECTED]> > To: <vortex-l@eskimo.com> > Sent: Monday, February 19, 2007 9:54 PM > Subject: [Vo]: Lifter aerodynamics > > > >> An "ion-wind" may produce enough force to let the lifter hover, but can >> it produce enough force to let the lifter (and its expanded >> electro-aeordynamic profile) _ascend_ through the air? >> >> Harry > >
