Skin friction

Skin friction drag. Drag generated between air molecules and the solid surface of the aircraft.
Slant range. The horizontal distance from the aircraft antenna to the ground station, due to line-of-sight transmission of the DME signal.

Skin Friction: That portion of drag which is covered by the movement of a fluid (e.g. air) over the surface of a body (e.g. aerofoil). The rougher the surface the greater the skin friction.

skin friction
The leading edge of a wing will always produce a certain amount of friction drag ...

As a fluid moves across a surface, a certain amount of friction (called skin friction) occurs between the fluid and the surface, which tends to slow the moving fluid.

This is the sum of the form and skin friction drag calculated at zero incidence.
See also: Induced Drag.
Propeller ...

The larger fuselage size causes more skin friction drag and wave drag. Hydrogen is about one-third of the weight of kerosene jet-fuel for the same amount of energy.

Adverse pressure gradients, surface roughness, heat and acoustic energy all examples of destabilizing influences. Once the boundary layer transitions, the skin friction goes up. This is the primary result of a turbulent boundary layer.

11Of course a small amount energy is required, because of skin friction and induced drag, but this is very small, out of all proportion to the energy that the air parcel transforms internally, from kinetic energy to pressure and back again.

It includes the form drag and skin friction associated with the fuselage, cockpit, engine cowlings, rotor hub, landing gear, and tail boom to mention a few. Parasite drag increases with airspeed.

See also: Drag, Skin, Fuselage, Aircraft, Wing