Jet (fluid)

A jet is an efflux of fluid that is projected into a surrounding medium, usually from some kind of a nozzle, aperture or orifice. Jets can travel long distances without dissipating. In the Earth's atmosphere there exist jet streams that travel thousands of miles.

Jet fluid has higher momentum compared to the surrounding fluid medium. In the case where the surrounding medium is assumed to be made up of the same fluid as the jet, and this fluid has a viscosity, then the surrounding fluid near the jet is assumed to be carried along with the jet by a process called entrainment.

Some animals, notably cephalopods use a jet to propel themselves in water. Similarly, a jet engine as it name suggests, emits a jet used to propel rockets, aircraft, jetboats, and submarines.

See also

• Jet stream, a high level wind in the Earth's atmosphere
• Jet engine, any machine propelled by a jet
• Jet nozzle, how a jet is formed
• Jet damping, a jet carries away angular momentum from a device emitting it
• Jet of blood

References

• Pijush K. Kundu and Ira M. Cohen, "Fluid mechanics, Volume 10", Elsevier, Burlington, MA,USA (2008), ISBN 978-0-12-373735-9
• Fluid Mechanics webpage with video, Q&A etc