Let's Reduce the Lift Drag of a Wing, Part 1
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- Опубликовано: 7 сен 2020
- If you need to have a low aspect ratio on your ultralight airplane wing in order to save weight, then you may want to figure out how to reduce the lift drag created by that low aspect ratio. In this video we look at what we can do to a wing's planform to decrease the lift drag.
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Disclaimer: If you use any of the information that you see on this video on a project of your own, YOU become the engineer and responsible party for your project. It is possible that miscalculations were made in the production of this video. Since you are now the engineer for your project, you must verify the information that you use. 
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Have you ever looked at Albion H Bowers' talks on the adding twists to wings to produce proverse yaw? It's another solution beyond the elliptical wing shape. First time on your channel, thanks for the easy listening, I'll have to listen through your videos.
I have not heard about Albion Bowers. Thanks for the tip.
Good !!
Induced drag is somewhat proportional to the lift generated. Reduced lift gives less drag and more speed but the takeoff and landing speeds are increased. Parasitic drag is rationalized when the solution is complicated and hard to comprehend.
How much does the airplane weigh?
How fast are you willing to go before leaving the ground?
I agree with what you have said. For the airplanes that I'm designing we have requirements that answer, either directly or indirectly your two questions and there is very little wiggle room. The empty weight of an U.S ultralight airplane is less than 254 lbs. It will rarely be less than 220. The maximum stall speed is 24 kts. This stall speed requirement then indirectly determines the lift off speed. The maximum level cruise speed is 55 kts. The empty weight limit and stall speed put significant constraints on our design. If we want to try to get more performance out of our airplane we need to look at other design tradeoff issues like playing with wing planform and tip shape to see what we can do. That is what I'm exploring in this video series.
probably a dumb question, but why is the ar of an elliptical Wing 4.5?
(Sry for my Bad english as always)
I made the Aspect Ratio of all of the wings the same so that I could compare them. They all have the same wing span and the same surface area. That gives them all the same aspect ratio. I chose AR=4.5 since that provides a light weight wing for an ultralight airplane but a poor coefficient of lift drag.
Ultralight Airplane Workshop, oh, ok now i get it, thanks!
That Low Aspect Wing takes more power to fly,,,,,More power means more engine weight,,,,so where is
your nonogram to find that optimum point?
You are correct if I want to maintain the same speed then I need more thrust. As long as I have thrust to spare that is not a problem. Just can't fly as far. As to what the optimum would be is a question that I like. A good idea for a new video. Thanks.
CSV = "Comma Separated Values", not "Comma Separated Variable".
Darn. That one got past me. You are absolutely right.