BOUNDARY LAYER

wing boundary layer The type of operation for which an airplane is intended has a very important bearing on the selection of the shape and design of the wing for that airplane. Boundary layer effects play a very important part in determining the drag for the aircraft.  Thus, the wing should be designed to minimize the drag.

AERODYNAMICS- DESIGN POINT OF VIEW

AERODYNAMICS

LIFT AND DRAG

Lift is the force due to the difference in the pressure between the lower and upper surfaces, multiplied by the planform area of the surface.

The pressure difference between the upper and lower surfaces is adjusted by adjusting the surface geometry and attitude to the oncoming flow. In low-speed flows of air (<0.3 times the speed of sound, or Mach 0.3), there are 3 main ways of creating such a pressure difference:

LIFT OF AIRCRAFT

LIFT OF AIRCRAFT 

There are several "definitions" of lift that may be found by searching through the relevant literature but only one that is really fundamentally correct.