What action does induced drag refer to?

Induced drag refers specifically to the drag that occurs as a direct result of the generation of lift by an airfoil, such as a wing. When an aircraft is in flight and the wing creates lift, it also causes a corresponding increase in drag, known as induced drag. This type of drag arises from the airflow around the wing and the formation of vortices at the tips of the wings. These vortices are a consequence of high-pressure air from below the wing moving to the lower pressure area above the wing, which creates turbulence and drag.

Understanding that induced drag is intrinsic to the airfoil's operation helps in grasping various aerodynamic principles, including how the design and shape of a wing influence overall aircraft performance. Recognizing the relationship between lift and drag can inform pilots and engineers on how to optimize flight efficiency and performance at different speeds and conditions.