Wake Turbulence & Clean Configurations

[sldauby]

Hey guys,

I am trying to understand wake turbulence and its effects on other aircraft. However, one thing (at the moment) is bugging me...

Why are wingtip vortices more "dangerous" in 'clean' configurations (flaps and gear up) than 'dirty' configurations? What is the "technical" reason for this?

Here is my thinking:

- Vortices are a byproduct of lift.
- More lift is produced at higher airspeeds (proportional to velocity squared).
- However, flaps are used to generated more lift at slow airspeeds...but wing area is not considered in the lift equation.
- However, lift coefficient is considered in the lift equation. Flaps reduce angle of attack required for slower airspeeds with the added lift. This reduces the lift coefficient, resulting in less lift required.
- More lift is required with flaps up in order to remain airborne (when airspeed is slow enough to warrant the use of flaps).

Technically, I am "stuck" here...

What am I missing? Should I be looking at something else than the lift equation?

Thanks.