kool kitty89
Senior Master Sergeant
Claidmore, a fixed slot would increase drag (either a device put in front of the wing or a slot cut into the wing), yes, but the automatic stats are operating beyond the wing's normal flight envleope. Without the slats the wing would exceed critical AoA and stall much earlier.
There is a small period in AoA where the slats begin to extend prior to where the wing's normal Clmax, which I would assume would increase drag somewhat compared to an unslatted wing, but this region is relatively small.
If the slats were extended all the time (ie when unnecessary) it would certainly be detrimental, but that's the point of a slat rather than a slot: they are only in use when needed.
And this:
To improve the L/D the increase in lift provided by the increased AoA acheivable with the slats would have to be greater than the coresponding increase in drag.
It's also in direct opposition to that chart I listed.
There is a small period in AoA where the slats begin to extend prior to where the wing's normal Clmax, which I would assume would increase drag somewhat compared to an unslatted wing, but this region is relatively small.
If the slats were extended all the time (ie when unnecessary) it would certainly be detrimental, but that's the point of a slat rather than a slot: they are only in use when needed.
And this:
seems rather odd to me.The same article says that leading edge devices increase drag, but the lift/drag ratio is improved.
To improve the L/D the increase in lift provided by the increased AoA acheivable with the slats would have to be greater than the coresponding increase in drag.
It's also in direct opposition to that chart I listed.