What is the aerodynamic advantage to a cuffed wing like this Cirrus?
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1$\begingroup$ I'm sure I read about how wings are designed to account for stalling at different times in this e-book, but skimming thru quickly I don't see it. <av8n.com/how/#contents> $\endgroup$– CrossRoadsApr 6, 2018 at 15:18
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$\begingroup$ related: aviation.stackexchange.com/q/30921/1467 $\endgroup$– FedericoApr 6, 2018 at 15:39
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$\begingroup$ Related: What does the zig-zag pattern on Hawker Hunter's leading edge represent? $\endgroup$– foootApr 6, 2018 at 16:23
1 Answer
Here we go: http://whycirrus.com/engineering/stall-spin.aspx
Spin Prevention
Cirrus chose, in the very earliest stages of designing the SR20 to take on the challenge: to minimize the risks associated with inadvertently stalling an airplane. The approach chosen was to employ wing technology developed by NASA reducing the potential for spin entry after an inadvertent stall. The most visible aspect is the discontinuous leading edge dividing the wing into distinct parts.
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How does this wing design work?
The outboard section of the Cirrus wing flies with a lower angle of attack than the inboard section. When the inboard section, which produces much of the lift, stalls the outboard section, where the ailerons are, is still flying. The result is that a stalled Cirrus airplane can be controlled intuitively using aileron.
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2$\begingroup$ That makes a lot of sense, nice find! It kind of makes me wonder why we don't see it on more designs though $\endgroup$– GeoffApr 6, 2018 at 15:28
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$\begingroup$ Reading the page, it seems to appear on other more current designs as well. I have micro-vortex generators on my plane that keep the airflow laminar in place longer with higher angle of attacks, keeps the airplane really responsive at low airspeeds and harder to stall. <microaero.com> They work really well, help to really shorten & soften my landings. $\endgroup$ Apr 6, 2018 at 15:58
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2$\begingroup$ Good luck to anyone that gets used to those handling characteristics when they next fly something that doesn't have this feature or lots of washout! $\endgroup$ Apr 6, 2018 at 16:02
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2$\begingroup$ @CrossRoads: Are you aware you keep posting broken links? It looks like you keep putting them in
<>
for some reason, and the>
gets interpreted as part of the link. $\endgroup$ Apr 7, 2018 at 1:19 -
1$\begingroup$ @Geoff: It is a kludge that is slapped on a misbehaving wing after design. A better way is to design washout into the wing and to use different airfoils for the inner and outer wing. This step causes a jump in lift which is bad for induced drag. In short, the wing becomes less efficient in creating lift that way. $\endgroup$ Apr 7, 2018 at 8:07