Drag (physics)
Videos
In fluid dynamics, drag, sometimes referred to as fluid resistance, and also known as viscous force, is a force acting opposite to the direction of motion of any object moving with respect to a surrou
Concorde with short tail spike.
Concorde with longer tail spike which gave lower wave drag.
Hawk aircraft showing base area above circular engine exhaust
Boundary layer
Videos
In physics and fluid mechanics, a boundary layer is the thin layer of fluid in the immediate vicinity of a bounding surface formed by the fluid flowing along the surface. The fluid's interaction with
The boundary layer around a human hand, schlieren photograph. The boundary layer is the bright-green border, most visible on the back of the hand (click for high-res image).
Ludwig Prandtl