Plain English Meaning

When air speeds up, its pressure drops; when it slows down, its pressure rises. On a wing, air moving faster across the top has lower pressure than the slower-moving air underneath, and that pressure difference helps lift the wing.

Full Definition

A principle of fluid dynamics stating that within a steady flow of air or fluid, an increase in the speed of the flow is accompanied by a decrease in its static pressure, and a decrease in speed is accompanied by an increase in pressure. In aviation, this principle helps explain how a difference in pressure between the upper and lower surfaces of an airfoil contributes to the production of lift.

Context Anchor

Seen in basic aerodynamics when studying how airflow around a wing helps create lift.

Derivation

Named after Daniel Bernoulli, an 18th-century Swiss mathematician who described the relationship between fluid speed and pressure. 'Differential' simply means 'a difference between' — here, the difference in pressure between two regions of moving air.