Bernoulli’s principle is named for Daniel Bernoulli, who presented it in 1738, and it concerns the relationship between pressure and flow speed in fluids.
In its simplest form, Bernoulli’s principle states that increasing flow speed in fluids corresponds to decreasing pressure, and vice versa.
Application of Bernoulli’s Principle – Airplane wings and Sails
An important example is in aviation. The airplane wing is a beautiful example of Bernoulli’s principle in action.
The wing is tilted upward at a small angle and the upper surface is longer, causing air to flow faster over it.
That means a higher flow speed on the top of the wing than on the bottom.
The pressure on top of the wing is therefore reduced, creating a net upward force or lift.
Figure (a) shows the characteristic shape of an airplane wing.
Figure (b) shows that the Sails also have the characteristic shape of a wing.
The wind velocity near the front side of the sail > wind velocity at the back end of the sail.
The pressure on the front side of the sail, Pfront , is lower than the pressure on the back of the sail, Pback .
This results in a forward force and even allows you to sail into the wind.