Nozzle

A nozzle is a mechanical device designed to control the characteristics of a fluid flow as it exits from an enclosed chamber into some medium.

What is a nozzle[]

A nozzle is generally a pipe or tube of varying diameter, that is used to direct or modify the flow of a liquid or gas.

Function[]

Nozzles are frequently used to control the rate of flow, direction, and/or the pressure of the stream that emerges from them.

Different types[]

Nozzles can be described as convergent (narrowing down from a wide diameter to a smaller diameter in the direction of the flow) or divergent (expanding from a smaller diameter to a larger one) or de Laval nozzles/convergent-divergent (CD nozzles).

Convergent nozzles accelerate fluids, but do not exceed the speed of sound in the fluid due to sonic choking at the narrowest point. Divergent nozzles slow fluids, if the flow is subsonic, but accelerate sonic or supersonic fluids. Convergent-divergent nozzles accelerate fluids that have choked in the convergent section to supersonic speeds.

Rocket engines and supersonic jet engines thus use CD nozzles, whereas subsonic jet engines use convergent nozzles.

Magnetic nozzles have also been proposed for some types of propulsion, in which the flow of plasma is directed by magnetic fields instead of walls made of solid matter.

High velocity nozzles[]

Frequently the goal is to increase the kinetic energy of the flowing medium at the expense of its pressure energy and/or internal energy. Very common use which almost everybody is seen is the nozzle used for fire fighting by the fire fighting organisation.

Spray nozzles[]

Many nozzles atomise liquids. Often this involves Venturi tubes.

These kinds of nozzles are used for spray painting, perfumes, carburettors for internal combustion engines, spray on deodorants [1], antiperspirants [2] and many other uses.

Shaped nozzles[]

Some nozzles are shaped to produce a stream that is of a particular shape. For example Extrusion molding is a way of producing lengths of metals or plastics or other materials with a particular cross-section.

Boomless nozzles[]

They can be used with ATV sprayers or Ute sprayers. Ideal for firebreaks, rough country spraying & locust control. In Australia, the brand Rapid Spray^[1] manufactures a wide range of similar products.