The essence of wing lift is discussed.
Without the engine's push, the pressure difference of the wing will not be generated. For example, if you don't push your foot, your feet will not create pressure on the ground.
The glider uses the energy of nature. So we need to drag gliders into the air so that it gets energy first.
Observe, on top of the wings, first is to guide the flow, the flow direction is more inclined upward (a arrow), and then again into a downward sloping airflow (b direction), change of flow direction of the strong, so the top wing will produce relatively large negative pressure. At the bottom of t...