A jet is a stream of

fluid In physics, a fluid is a liquid, gas, or other material that may continuously motion, move and Deformation (physics), deform (''flow'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are M ...

that is projected into a surrounding medium, usually from some kind of a

nozzle A nozzle is a device designed to control the direction or characteristics of a fluid flow (specially to increase velocity) as it exits (or enters) an enclosed chamber or pipe (material), pipe. A nozzle is often a pipe or tube of varying cross ...

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

or orifice. Jets can travel long distances without dissipating. Jet fluid has higher speed compared to the surrounding fluid medium. In the case that the surrounding medium is assumed to be made up of the same fluid as the jet, and this fluid has

viscosity Viscosity is a measure of a fluid's rate-dependent drag (physics), resistance to a change in shape or to movement of its neighboring portions relative to one another. For liquids, it corresponds to the informal concept of ''thickness''; for e ...

, some of the surrounding fluid is carried along with the jet in a process called entrainment. Some animals, notably

cephalopods A cephalopod is any member of the molluscan Taxonomic rank, class Cephalopoda (Greek language, Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral symm ...

, move by jet propulsion, as do

rocket engine A rocket engine is a reaction engine, producing thrust in accordance with Newton's third law by ejecting reaction mass rearward, usually a high-speed Jet (fluid), jet of high-temperature gas produced by the combustion of rocket propellants stor ...

s and

jet engine A jet engine is a type of reaction engine, discharging a fast-moving jet (fluid), jet of heated gas (usually air) that generates thrust by jet propulsion. While this broad definition may include Rocket engine, rocket, Pump-jet, water jet, and ...

Applications

Liquid jets are used in many different areas. In everyday life, you can find them for instance coming from the water tap, the showerhead, and from spray cans. In agriculture, they play a role in

irrigation Irrigation (also referred to as watering of plants) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has bee ...

and in the application of crop protection products. In the field of medicine, you can find liquid jets for example in

injection Injection or injected may refer to: Science and technology * Injective function, a mathematical function mapping distinct arguments to distinct values * Injection (medicine), insertion of liquid into the body with a syringe * Injection, in broadca ...

procedures or inhalers. Industry uses liquid jets for waterjet cutting, for coating materials or in

cooling tower A cooling tower is a device that rejects waste heat to the atmosphere through the cooling of a coolant stream, usually a water stream, to a lower temperature. Cooling towers may either use the evaporation of water to remove heat and cool the ...

s. Atomized liquid jets are essential for the efficiency of

internal combustion engine An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal comb ...

s. But they also play a crucial role in research, for example in the study of

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

phase transition In physics, chemistry, and other related fields like biology, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. Commonly the term is used to refer to changes among the basic Sta ...

s, extreme states of matter, laser plasmas, High harmonic generation, and also in

particle physics Particle physics or high-energy physics is the study of Elementary particle, fundamental particles and fundamental interaction, forces that constitute matter and radiation. The field also studies combinations of elementary particles up to the s ...

experiments. Also some animals, notably

, move by jet propulsion. Gas jets are found in

s and

s. Microscopic liquid jets have been studied for their potential application in noninvasive transdermal

drug delivery Drug delivery involves various methods and technologies designed to transport pharmaceutical compounds to their target sites helping therapeutic effect. It involves principles related to drug preparation, route of administration, site-specif ...

References

* Pijush K. Kundu and Ira M. Cohen, "Fluid mechanics, Volume 10", Elsevier, Burlington, MA, USA (2008), * Fluid dynamics {{Fluiddynamics-stub

Applications

See also

References