474
P. Liu
Fig. 7.35 Two-layer and three-layer wing aircraft (German Fokker Dr.I three-layer
wing fighter)
The wing lift-to-drag ratio defined by Lilienthal is
K =
L
D
=
C L
C D
This is a measure of wing performance and efficiency and plays an important role in wing design. The definition of characteristic area is different in
aerodynamics and general fluid mechanics. In aerodynamics, the characteristic area S of the wing generally refers to the horizontal projected area of the
P. Liu
Fig. 7.35 Two-layer and three-layer wing aircraft (German Fokker Dr.I three-layer
wing fighter)
The wing lift-to-drag ratio defined by Lilienthal is
K =
L
D
=
C L
C D
This is a measure of wing performance and efficiency and plays an important role in wing design. The definition of characteristic area is different in
aerodynamics and general fluid mechanics. In aerodynamics, the characteristic area S of the wing generally refers to the horizontal projected area of the