According to Bernoulli's principle, what happens to fluid pressure at points of increased velocity?

Bernoulli's principle states that in a steady, incompressible flow of a fluid, an increase in the fluid's velocity occurs simultaneously with a decrease in pressure. This relationship arises from the conservation of energy principle applied to fluid dynamics, which indicates that the total mechanical energy of flowing fluid remains constant if no external work is performed and there are no friction losses.

In more technical terms, as fluid accelerates through a constriction or an area where its velocity is higher, the kinetic energy of the fluid increases. In order to conserve total energy, the potential energy in the form of pressure must decrease. Therefore, at points where the fluid's velocity is increased, the pressure in that region must decrease correspondingly. This is a foundational concept in fluid mechanics and is crucial for understanding how various fluid systems operate, including pipelines, airfoils, and various hydraulic systems.

In essence, this principle explains many practical phenomena in fluid flow, such as why airplane wings generate lift or how carburetors work in engines, making it a core principle in both theory and application.