What does profile drag consist of?

Profile drag primarily consists of form drag and skin friction.

Form drag arises from the shape of the aircraft as it moves through the air. This type of drag is influenced by the pressure difference created between the front and rear of the aircraft due to its shape, which affects how air flows around it. The more streamlined the aircraft is, the lower the form drag will be.

Skin friction, on the other hand, is caused by the interaction of air with the surface of the aircraft. It results from the viscosity of air and behaves similarly to friction due to a surface moving through a fluid. Skin friction is influenced by the texture of the aircraft's surface; smoother surfaces generally lead to lower skin friction drag.

Profile drag is important to understand in aviation as it impacts the overall aerodynamic efficiency of an aircraft and contributes significantly to the drag experienced during flight. By focusing on minimizing both form drag and skin friction, aircraft designers aim to enhance performance and fuel efficiency.