flap setting are everything, even on the same variant,
it also depends on the crosswind component,
or if the flap edge discontinuity is ingested into the vortex or not...
ingested..adds to the rollup velocity from the small core outward...strong initial vortex, may dissipate faster....
not ingested...large core vortex is not accelerated by discontinuity vortex...not as strong as above, but may be longer lasting
then there is crosswind, just like the FAA says, the vortex is generated normally, then drifts away from the flightpath.. really?
reality...one really strong vortex, not coupled, on its own..VERY strong vortex...long lived and indeterminate behaviour
