Hello LambOfGod
Seems like we're a couple of guys wondering about the same questions.
Look somewhat back in tech log, maybe three pages, and you'll find the title "strongest wing tip vortices when slow, clean and heavy. BUT WHY?" by ludovico. Maybe that can help.
I also believe that you have slightly less lift during climb, and climb is due to excess thrust.
On the other hand I'm not so sure if I agree with zerozero on the description of induced drag. He does state clearly that he describes it within the parameters of only Newtonian thought, and maybe one defines vectors different then. I'm open for discussion.
Still:
'Because lift is a force, it is a vector quantity, having both a magnitude and a direction associated with it. Lift acts through the center of pressure of the object and is directed
perpendicular to the flow direction.'
What is Lift?
It does not tilt with angle of attack as long as the flow direction is the same (let's assume level flight at different airspeeds). That would be the resultant force from lift and drag, but not lift.
By using both Newton, Coanda and Bernoulli to describe lift it seems like we have more wingtip vortices (induced drag) when we're clean, slow and heavy.
Here's my thoughts about it in the thread mentioned above:
Hello ludovico
I asked the exact same thing here at tech log some time ago and couldn't wrap my head around it, but it seems Brian Abraham has a really good point.
I was thinking that flap couldn't affect the vortex since flying an airplane in a given IAS has to produce the same amount of lift, and hence induced drag, whether it is configured with flaps or not. Here is where I guess I was wrong:
A vortex being dependent of the downwash angle from the airfoil to the direction of flight and the pressure differential between the upper- and lower side of the airfoil, is then dependent of the aspect ratio of the wing.
As we read during our studies that's why the gliders have long wings.
But.. lowering flaps shifts the centre of pressure laterally towards the area of the flaps due to the increased camber and downwash angle. When maintaining the same amount of total lift this means less pressure differential toward the wingtips, as if there was a higher aspect ratio.
Meaning smaller vortex when lowering flaps.
As said so many times in this thread.. this is just my theory. If I am corrected I see that as a chance of learning.
I hope this may have been of some help.