How Things Fly: How Do Lift and Drag Work at Supersonic Speeds?

How Do Lift and Drag Work at Supersonic Speeds?

The patterns of air pressure that create lift and drag at supersonic speeds are dramatically different from those that create lift and drag at subsonic speeds.

When an aircraft approaches the speed of sound, the airflow over the wing reaches supersonic speed before the airplane itself does, and a shock wave forms on the wing. The airflow behind the shock wave breaks up into a turbulent wake, which increases drag.

When the airplane exceeds the speed of sound, a shock wave forms just ahead of the wing's leading edge. The shock wave that formed on the wing is now at the trailing edge.

When the wing is tilted upward, a shock wave forms below its leading edge, and an expansion wave (or sometimes a weaker shock wave) forms above its leading edge. The higher pressure behind the shock wave and lower pressure behind the expansion wave result in a single force that pushes the wing both upward and backward. The upward part of this force is lift; the backward part of this force is drag.

(Rev. 02/16/99)

When an aircraft approaches the speed of sound, the airflow over the wing reaches supersonic speed before the airplane itself does, and a shock wave forms on the wing. The airflow behind the shock wave breaks up into a turbulent wake, which increases drag.
	When the airplane exceeds the speed of sound, a shock wave forms just ahead of the wing's leading edge. The shock wave that formed on the wing is now at the trailing edge.
When the wing is tilted upward, a shock wave forms below its leading edge, and an expansion wave (or sometimes a weaker shock wave) forms above its leading edge. The higher pressure behind the shock wave and lower pressure behind the expansion wave result in a single force that pushes the wing both upward and backward. The upward part of this force is lift; the backward part of this force is drag.