Winglets and Wake Turbulence

[minitour]

Now is it enough to make a difference to your 172 if you fly through the wake of a 757? I seriously doubt it....

That was my point....I was trying to make a very very tongue-in-cheek comment.

-mini

 

[MarineGrunt]

That was my point....I was trying to make a very very tongue-in-cheek comment.

-mini

Ah. I thought you were speaking in broader terms. I can be slow somethimes.............. (to the surprise of many!)

 

[minitour]

Ah. I thought you were speaking in broader terms. I can be slow somethimes.............. (to the surprise of many!)

slow is a relative term.....take that 135.....slow in that would be Vne + ??? in the 172....so see...its not so bad :beer:

 

[drinkduff77]

There was an article about this 3 or 4 months ago. The wake on the 757 is reduced by something like 30% with the winglets.

Check out

http://oea.larc.nasa.gov/PAIS/Concept2Reality/winglets.html

This is from the same article in the "Wake-Vortex Hazard" chapter:

Langley researchers were constantly challenged by the complexity of the wake flow field for representative transports. Many concepts that appeared to affect the wake properties in the immediate roll-up area behind the generating aircraft were found to have little impact on the magnitude of roll upset at downstream distances representative of the location of trailing aircraft. Furthermore, it was found that numerous interacting vortices were shed by the typical transport in the landing configuration. For example, in addition to the vortices expected at the wingtips, strong vortices were also shed at the edges of wing trailing-edge flaps, and aft fuselage. As a result of these types of interactive vortex effects, some wingtip vortex control concepts that were known to provide beneficial effects for cruise drag (such as winglets) had little or no effect on the wake vortex hazard when the aircraft was in the flaps-down, landing approach configuration.

I'm not sure where you got that 30 percent number from. Seems kind of high and conflicts with the paragraph above.