The resistance, or skin friction, due to the viscosity of the air as it passes along the surface of a wing is called

The resistance, or skin friction, due to the viscosity of the air as it passes along the surface of a wing is called

• A. Profile drag
• B. Induced drag
• C. Form drag
• D. Parasite drag

Answer: (A)

The resistance produced by the air’s viscosity as it flows along the wing surface is skin-friction drag. This viscous shear acts along the surface and is a primary component of the drag you get from the wing’s interaction with the air. In drag classifications, the surface-related portion is grouped into profile drag, which is the total drag due to the wing’s shape and its surface, combining friction drag and the pressure-based form drag. Form drag comes from pressure differences around the wing, not from viscosity, and induced drag is tied to lift generation, not surface shear. Parasite drag covers all non-lift-producing drag, including both skin friction and form drag, but the specific surface friction described here is best described as profile drag.

The resistance produced by the air’s viscosity as it flows along the wing surface is skin-friction drag. This viscous shear acts along the surface and is a primary component of the drag you get from the wing’s interaction with the air. In drag classifications, the surface-related portion is grouped into profile drag, which is the total drag due to the wing’s shape and its surface, combining friction drag and the pressure-based form drag. Form drag comes from pressure differences around the wing, not from viscosity, and induced drag is tied to lift generation, not surface shear. Parasite drag covers all non-lift-producing drag, including both skin friction and form drag, but the specific surface friction described here is best described as profile drag.