What principle does Bernoulli's theory describe?

Bernoulli's theory fundamentally explains how the pressure of a fluid changes in relation to its velocity. Specifically, it states that as the speed of a fluid (including air) increases, the pressure within that fluid decreases. This principle is crucial for understanding lift generation in aviation, as it helps to explain how the shape of an airfoil (airplane wing) works.

When air flows over the curved top surface of a wing, it travels faster than the air flowing under the flatter bottom surface. According to Bernoulli's theory, the faster-moving air above the wing results in lower pressure, while the slower-moving air below the wing maintains higher pressure. This difference in pressure creates an upward lifting force on the wing.

This understanding is essential for pilots and aerospace engineers, as it provides insight into how changes in wing design, orientation, and speed can affect an aircraft's lift capabilities during flight maneuvers.