skin friction/surface friction drag

skin friction/surface friction drag

skin friction/surface friction drag
Airflow along a rough surface.
skin friction/surface friction drag
Airflow along a smooth surface.
Drag caused by the unevenness in the skin of a body. The layers of air near the surface are retarded, and the speed of the airflow increases as the distance from the skin increases. To reduce the skin friction, the surface should be smoothened to the maximum extent. Skin friction is a component of parasite drag. It increases considerably if the airplane's surfaces are dirty and rough. The skin friction or surface friction drag is determined by the total surface area of the aircraft, the coefficient of the viscosity of the air, and the rate of change of the velocity across the airflow.