A jet is a stream of fluid that is projected into a surrounding medium, usually from some kind of a nozzle,

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An ...

orifice An orifice is any opening, mouth, hole or vent, as in a pipe, a plate, or a body * Body orifice, any opening in the body of a human or animal *Orifice plate, a restriction used to measure flow or to control pressure or flow, sometimes given specia ...

. Jets can travel long distances without dissipating. Jet fluid has higher momentum 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 a

viscosity The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the inte ...

, the surrounding fluid is carried along with the jet in a process called

entrainment Entrainment may refer to: * Air entrainment, the intentional creation of tiny air bubbles in concrete * Brainwave entrainment, the practice of entraining one's brainwaves to a desired frequency * Entrainment (biomusicology), the synchronization o ...

. Some animals, notably cephalopods, move by

jet propulsion Jet propulsion is the propulsion of an object in one direction, produced by ejecting a jet of fluid in the opposite direction. By Newton's third law, the moving body is propelled in the opposite direction to the jet. Reaction engines operatin ...

, as do

rocket engine A rocket engine uses stored rocket propellants as the reaction mass for forming a high-speed propulsive jet of fluid, usually high-temperature gas. Rocket engines are reaction engines, producing thrust by ejecting mass rearward, in accorda ...

s and jet engines.

Applications

Liquid jets are used in many different areas. In everyday life, you can find them for instance coming from the

water tap A tap (also spigot or faucet: see usage variations) is a valve controlling the release of a liquid or gas. Nomenclature United Kingdom * Tap is used in the United Kingdom and most of the Commonwealth for any everyday type of valve, parti ...

, the

showerhead A shower is a place in which a person bathes under a spray of typically warm or hot water. Indoors, there is a drain in the floor. Most showers have temperature, spray pressure and adjustable showerhead nozzle. The simplest showers have a ...

, and from

spray cans Spray or spraying commonly refer to: * Spray (liquid drop) ** Aerosol spray ** Blood spray ** Hair spray ** Nasal spray ** Pepper spray ** PAVA spray ** Road spray or tire spray, road debris kicked up from a vehicle tire ** Sea spray, refers to ...

. In agriculture, they play a role in

irrigation Irrigation (also referred to as watering) 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 been devel ...

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 towers 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 process heat and ...

. Atomized liquid jets are essential for the efficiency of

internal combustion engines 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 combust ...

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

phase transitions In chemistry, thermodynamics, and other related fields, 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 states of ...

extreme states of matter Extreme may refer to: Science and mathematics Mathematics *Extreme point, a point in a convex set which does not lie in any open line segment joining two points in the set *Maxima and minima, extremes on a mathematical function Science *Extremop ...

, laser plasmas, High harmonic generation, and also in

particle physics Particle physics or high energy physics is the study of fundamental particles and forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) an ...

experiments. Also some animals, notably cephalopods, move by

. Gas jets are found in

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

drug delivery Drug delivery refers to approaches, formulations, manufacturing techniques, storage systems, and technologies involved in transporting a pharmaceutical compound to its target site to achieve a desired therapeutic effect. Principles related to dr ...

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