First of all, what is Drag? Drag is the force that resists movement of of an aircraft through the air. It slows the aircraft in flight by limiting the forward speed of the airplane. There are two main types of drag: parasite drag and induced drag.
An aircraft’s shape, construction-type, and material is what causes parasite drag since the planes surface interferes with the smooth airflow around the plane. Parasite drag is split into three types: Form drag, Interference drag, and Skin friction drag.
It happens from the turbulent wake caused by the separation of airflow from the surface of a structure.
It arises when the airflow around one part of the plane reacts with the airflow around the adjacent part.
Skin friction drag
This type of drag is created by the roughness of the aircraft’s surface. Even though the plane’s surface might seem smooth, but it’s actually kind of rough.
Induced drag is the result of lift and is made by the passage of an aerofoil through the air. The pressure difference from top to bottom of the wing results in spillage around the wing tips. The downwash from the wing tips effects local angle of attack with more drag component on a finite wing. For a more in depth explanation of induced drag, check the below references.
Book: Guided Flight Discovery
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