Dave,
A while back I sent you some comments on my admittedly amateurish approach to 2M based on Martin Simons work back in the 80's. AR's are around 6 - max chord around 16", min = around 8" Would you care to discuss how this approach fits into your current discussion?
RVC
At 12:59 PM 2/18/2005 -0500, you wrote:
In a message dated 2/18/2005 9:11:49 AM Central Standard Time,
[email protected] writes:
Changing aspect ratio with a fixed span does not affect induced drag (if we
ignore that the weight of the structure changes). Induced drag is
proportional to the span loading squared (the formula below is obtained by manipulating
the one above Cdi=Cl^2/(Pi*AR)):
D = (W/L)^2/(Pi*q), where q = rho*V^2/2
********
Oleg,
This does not seem to be dimensionally correct.
In english units D is in lbs., V is in ft/sec, W/L is in lb/ft^2, and rho
(density) is in slugs/ft^3 (gotta love those english density units!).
Converting from density to weight (density * g ) gives the left side in lbs and the
right side in lbs/ft^2.
I believe the missing term is the average chord (Cavg^2).
Absent that, I'll generally be in agreement with your comments with a few caveats:
Assuming the following is correct (my derivation of the same manipulation you've done using the equations Lift = q * Cl * A, Drag = q * Cd * A, where A is the wing area):
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