737-800 Wing Things(!??)

[Mike Blackburn]

Hi All

A quick (and silly) question. When flying on Ryanair 737-800 recently, I noticed a number of small projections on the upper surface of the wing, behind the slats area. They are about 2inches high, and are aligned in the direction of the airflow, which makes me suspect that they may be vortex generators or something like that. Any one able to confirm this?
Thanks...

[TR4A]

vortex generators

[husqvarna]

I thought that for an aircraft wing it was desired to have laminar flow over the surface. Having turbulent flow would probably decrease skin friction, but wouldn't it also decrease lift as the air would slow down?

[TR4A]

Vortex generators work by mixing high-energy fluid (free stream air in this case) with the lower energy fluid found near the skin surface, called the boundary layer. This process is called re-energizing the boundary layer. The higher energy fluid is now more resistant to separation and allows for higher performance of the aircraft. Technically speaking a vortex generator increases the mean streamwise momentum of the boundary layer by drawing in high momentum fluid from the free stream.

Vortex generators can be used to improve the performance of aircraft in a variety of ways. If properly sized and positioned vortex generators can be used to lower the stall speed of an aircraft, improve stability and control during maneuvering, decrease turning radius, decrease takeoff distance and increase takeoff weight. For commercial aircraft this can mean higher payloads and increased safety. While the general aviation pilot will enjoy better maneuverability as well as the increase in safety.

[Mike Blackburn]

Thanks for the answer and explanation. Helps a lot.