I think your baulked flow beneath the wing picture, where the wing is within a fraction of a chord distance of the ground (Fig 4 of your diagram) is effectively describing a sort of `ram-air hovercraft', where there is an enhanced static pressure beneath the vehicle - plus a lot of extra drag, as you're slowing more mass down in the horizontal direction than you would a long way above the ground.
Yes, I would agree with that for that particular picture. As I said, my hope was that people would interpolate for greater heights, although that of course depends to some extent on there being some linearity.
My comments really were based on the data of that NACA TN, but now I come to look at that more closely I see that also was biased towards quite low ground heights. The trend to increased pressures under the wing is still there though even at heights of around 30% span which is reasonable for a modern design close to touchdown. It is MUCH less obvious however and, again looking more closely, I see there is some increase in LE suction peak in this condition.
That may be enough to suggest that for what most would regard as 'normal' the ground effect can be simply regarded as due to increased circulation (arising from the 'mirror image' wing) which adds to the lower surface flow slowing down from the main wing circulation, and must also result in increased circulation around the main wing.
That would satisfy me - now back to Newton
