Originally Posted by
Roxy_Chick_1989
Thanks for the discussion, and many more questions have now popped up!!
Now onto another though, I notice alot of the modern airliners equipped for long range ops mainly utilise winglets, these aircraft obviously spend the majority of their time in the cruise. I believe winglets are used to reduce induced drag generated from the mainplane, however if these aircraft are spending the majority of time in CRZ (thence low AoA = low induced drag) how are winglets beneficial as all i see is a potential parasite drag increase. Im not out to reinvent the wheel, and i trust everything the engineers/designers have done. I am however very interested to know the reasoning behind this.
Not quite true in the reasoning there.
Low AOA means a low induced drag CD (i.e. drag coefficient). But there's also a low CL as well. That CL is able to support the weight of the aircraft thanks to a nice high airspeed multiplying up the CL to a good amount of Lift. That same kinetic pressure also multiplies the CD to give a fair amount of Drag. So while the saving in terms of induced CD may be small, the saving in terms of drag (hence fuel burn / range) is a fair amount, and often worth having.