#46




Yes, do tell!
Steve, stay on track here or start your own thread about your thingie please. : ) 
#47




Quote:
A2 = V1^2/V2^2 * A1 Plug in the original velocity  V1, the new velocity  V2, which is SMALLER, and the original wing area  A1, and the new area will be the result. As an example, if A1 was 88 sq. ft., V1 was 80 mph, and V2 was 70 mph, A2 would be 115 sq. ft., or 30% more. Not surprising, given the 14% decrease in speed, and the squared relationship. Induced drag is linearly related to wing area. It would rise by 30%. Harder to say exactly, but if we use a crude estimation of the power being linearly related to the area and related to the cube of the velocity, then: V2 = (A1/A2 * V1^3)^1/3 If A1/A2 = 88/115 (from before) = 0.76, and V1 = 200 mph, then: V2 = 182 mph. So we lose about 10% of the top end, for the 30% increase in wing area. All this is approximate, but it gives you the order of magnitude. All these equations drop out of the simple relationships for lift and drag. L = 1/2 * rho * V^2 * A * Cl D = 1/2 * rho * V^2 * A * Cd
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#48




Marc 
I SO appreciate your abilities and helpfulness... thank you is too feable and more would be less.... thank you John 
#49




That's a good answer. Let's say you want to increase the canard length by 30% instead the total wing area. Or maintain the wing length and increase the canard width. How would this apply?
I know I can dig for this stuff on the Roncz canard design and other resources but its more fun to get a simple answer for all of us whom are curious. 
#50




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Changing the ratio of canard area to wing area (or canard moment arm to wing moment arm) will change your CG range, stability, and deep stall susceptibility.
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#51




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#52




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In the case of canard area/length/chord, there's an interaction between size and CG position, which then leads to issues of main gear placement for rotation, elevator trim position in cruise, and deep stall susceptibility. There are MANY formulae involved in determining these relationships and behaviors. All of which are available in introductory aerodynamics and stability/flight dynamics texts.
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