What is a vortex when referring to planes / flying.?

Question

I have read this but i dont understand what or where a vortex is in reference to a plane.

The explanation should read: From HAB pilot:

This question appears in the 2/14/2007 FAA public question bank under knowledge code J27.

VORTEX STRENGTH

The strength of the vortex is governed by the weight, speed, and shape of the wing of the generating aircraft. The vortex characteristics of any given aircraft can also be changed by the extension of flaps or other wing configuration devices as well as by a change in speed. The greatest vortex strength occurs when the generating aircraft is heavy, clean, and slow.

Reference from "Pilot’s Handbook of Aeronautical Knowledge" (FAA-H-8083-25) Chapter 12-13.

--------------------------------------...

Answer 1

no need to answer but just take my two points and give my salute to the answerer in the order of their appearance (or answer).

Answer 2

VECTOR generators Michael? You likely mean VORTEX generators and they can never reduce the stall speed of a wing. Just the oposite. Vortex generators are used on the upper surface of a swept wing high speed aircraft for the purpose of keeping a shock wave from forming forward of the ailerons at transonic mach numbers. This prevents aileron buzz or flutter or the more serious aileron snatch.

But in answer to your question Paul, Victor is quite correct. Picture small horizontal tornados aft of the wing tips on a slow flying airplane.

Answer 3

In addition to Victor's excellent answer, vectors are sometimes generated by ... vector generators. On very light aircraft used for short-field operations where STOL performance is needed, some thin vertical plates of plastic or metal are added a bit aft of the wing's leading edge. That is done in the purpose of creating vortex above the wing and reduce the stall speed. Of course, just like slats, it also creates extra parasite drag when at cruise speed but I know bush pilots who swear by them.

(EDITED) Yes, Vortex and not vector; a typo from my part. But I fly a homebuilt Kitfox aircraft and many pilots fit that aircraft with vortex generators to increase the stall speed.

If you don't believe me, here is a site about it, even with a video:

http://www.cfisher.com/vg.html

Answer 4

If you injected smoke into the airstream at the wingtips, you would see miniature tornadoes trailing the plane. These are greater at take off than at any other time.  They can stay in the air in the path of takeoff for maybe 2 or 3 minutes and if you fly into the vortex with a smaller plane, you are in danger of damage or crashing. The resulting wake turbulence has caused some crashes.

Answer 5

An aircraft flies because the air above the wing has a lower pressure than the air below. The higher pressure air below pushes the wing up, creating lift. At the wingtips, the air below the wing is sucked upward over the tip into the low pressue area above the wing. As the air does this, it is spun violently into a vortex, like a tornado trailing back from the wingtip. A large aircraft like a Boeing 747 can generate huge vortices behind it, sometimes powerful enough to badly disturb a smaller aircraft. Here are a couple of pictures of planes in clouds that demonstrate this effect dramatically:

http://commons.wikimedia.org/wiki/Image:...

http://www.flyingstart.ca/FlightTraining...

http://www.airliners.net/photo/Virgin-At...

Very striking vortices can also be created by an airliners flaps and slats:

http://www.airliners.net/photo/FedEx-Exp...