I used my crude "disk balloons" analogy of airplane flight to predict the
induced drag upon an aircraft to be:
Drag force = 8 * (M * g)^2 / [ pi * span^2 * V^2 * density ]
M * g being aircraft weight, V is velocity of horizontal flight, and
"density" is the density of air.
How does this match conventional calculations of induced drag? The only
reference I have at hand is THEORY OF FLIGHT, in which I don't immediately
find a treatment of induced drag. If anyone here has offhand knowledge of
this issue, can they tell me if my above equation is totally bogus? Does
induced drag increase as aircraft weight^2, and decrease as 1/V^2, and as
1/span^2?
The above equation comes from the simplified physical model described
here:
(Note: I assume that the disk balloons contain "solid air", or that there
are membranes within the balloons which force the enclosed air to rotate
like a solid disk.)