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Old Feb 27, 2004, 04:33 AM
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Punta Gorda, FL
Joined Apr 2002
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1. The aircraft will be operating near the stall when carrying maximum weight. There are several interesting trade offs involved. On the one hand an untapered, untwisted wing is quick and simple to build accurately. On the other hand a wing that is designed for minimum induced drag will have a highly tapered planform as will a wing that is designed for minimum spar weight. However wings that are highly tapered have vicious tip stall characteristics that put the plane at serious risk of crashing when flown at low speeds and low altitudes.

2. No comment since I am a glider guy.

3.Winglets are hard to design and hard to build accurately but you might get extra points for design sophistication. With unlimited wing span beyond 10 feet the simplest way to decrease induced drag is to increase aspect ratio. You should look at the trade off betwen a simple, easy to build wing of high aspect ratio with good tip stall margin versus a more complex planform with tiplets and the associated tip stall tendencies. The higher the maximum lift coefficient of the airfoil,the more importance has to be assigned to induced drag reduction. So, airfoil(s) selection involves a trade off with the rest of the wing design. A drag budget is a useful tool in weighing design alternatives and establishing project priorities.

Most development projects take at least twice as long as planned so there is a trade off between complexity and simplicity when there is a deadline involved.

The less experienced the design team the more safety factors are appropriate in all aspects of the project.
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Last edited by Ollie; Feb 27, 2004 at 04:40 AM.
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