Bernoulli's Principle

Bernoulli's principle states that for a fluid flowing without friction, an increase in the fluid's speed occurs together with a decrease in its pressure or in its potential energy, expressing a form of the conservation of energy for flowing fluids. Swiss mathematician Daniel Bernoulli set out the principle in his 1738 book Hydrodynamica, deriving it from the relationship between a fluid's velocity and pressure along a streamline. The principle is commonly expressed through Bernoulli's equation, which states that the sum of a fluid's static pressure, its dynamic pressure associated with its velocity, and its hydrostatic pressure associated with its height remains constant along a streamline for an idealized, incompressible, frictionless flow. The principle underlies standard explanations of how an aircraft wing generates lift, the operation of a Venturi tube and carburetor, and the working of a pitot tube used to measure airspeed by comparing dynamic and static pressure.