The early history of aviation is full of crazy designs, so please allow me this one:
A span wise narrow gap in the wing halfway between the leading edge and the trailing edge.
The door to the gap would be aerodynamically balanced, it would open at slow speeds. The gap cross section would be nozzle shaped to accelerate the air from underneath the wing to the top side. Lowering its pressure.
At the wing root and tip there will be no gap.
The idea is similar to slotted flaps and slats, but with the aim of energizing the aft portion of the wing. Thereby combining slats and flaps into one. Would it work?
In other words, it would split the wing into two smaller wings.
I expect the answer to be no, but would love to know why.
Edit: edges below are meant to be curved.