Venturi effect

The reduction in fluid pressure that results when a fluid flows through a constricted section of a pipe.

The Venturi effect is a phenomenon in fluid dynamics where a fluid's velocity increases and its pressure decreases as it flows through a constricted section of a pipe or channel. This effect is named after the Italian physicist Giovanni Battista Venturi, who first observed it in the 18th century.

Diagram of the Venturi effect.

Principle

The Venturi effect is a direct consequence of the Bernoulli's principle, which states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy. When a fluid enters a constricted section of a pipe, its velocity must increase to maintain the continuity of flow, leading to a drop in pressure.

Illustration of fluid flow through a Venturi tube.

Applications

The Venturi effect has numerous applications in various fields:

• Aviation: Venturi tubes are used in aircraft to measure airspeed and to provide vacuum for gyroscopic instruments.
• Medicine: Venturi masks are used to deliver a precise concentration of oxygen to patients.
• Industrial: Venturi scrubbers are used to remove particles from industrial exhaust streams.

Aircraft venturi used for vacuum instruments.

Venturi tube

A Venturi tube is a device that utilizes the Venturi effect to measure the flow rate of a fluid. It consists of a tube with a constricted throat that causes a pressure drop, which can be measured to determine the flow rate.

Venturi tube in a physics laboratory.

Related pages

• Bernoulli's principle
• Fluid dynamics
• Flow measurement