Jet (fluid)
Encyclopedia
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 stream
s 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 rocket
s, aircraft
, jetboat
s, and submarine
s.
Fluid
In physics, a fluid is a substance that continually deforms under an applied shear stress. Fluids are a subset of the phases of matter and include liquids, gases, plasmas and, to some extent, plastic solids....
that is projected into a surrounding medium, usually from some kind of a nozzle
Nozzle
A nozzle is a device designed to control the direction or characteristics of a fluid flow as it exits an enclosed chamber or pipe via an orifice....
, aperture
Aperture
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture of an optical system is the opening that determines the cone angle of a bundle of rays that come to a focus in the image plane. The aperture determines how collimated the admitted rays are,...
or orifice. Jets can travel long distances without dissipating. In the Earth's atmosphere there exist jet stream
Jet stream
Jet streams are fast flowing, narrow air currents found in the atmospheres of some planets, including Earth. The main jet streams are located near the tropopause, the transition between the troposphere and the stratosphere . The major jet streams on Earth are westerly winds...
s that travel thousands of miles.
Jet fluid has higher momentum
Momentum
In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object...
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
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...
.
Some animals, notably cephalopods use a jet to propel themselves in water. Similarly, a jet engine
Jet engine
A jet engine is a reaction engine that discharges a fast moving jet to generate thrust by jet propulsion and in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets...
as it name suggests, emits a jet used to propel rocket
Rocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...
s, aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
, jetboat
Jetboat
A jetboat is a boat propelled by a jet of water ejected from the back of the craft. Unlike a powerboat or motorboat that uses a propeller in the water below or behind the boat, a jetboat draws the water from under the boat into a pump inside the boat, then expels it through a nozzle at the...
s, and submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...
s.
See also
- Jet streamJet streamJet streams are fast flowing, narrow air currents found in the atmospheres of some planets, including Earth. The main jet streams are located near the tropopause, the transition between the troposphere and the stratosphere . The major jet streams on Earth are westerly winds...
, a high level wind in the Earth's atmosphere - Jet engineJet engineA jet engine is a reaction engine that discharges a fast moving jet to generate thrust by jet propulsion and in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets...
, any machine propelled by a jet - Jet nozzle, how a jet is formed
- Jet dampingJet dampingJet damping or thrust damping is the effect of rocket exhaust removing energy from the transverse angular motion of a rocket. If a rocket has pitch or yaw motion then the exhaust must be accelerated laterally as it flows down the exhaust tube and nozzle...
, a jet carries away angular momentum from a device emitting it - Jet of bloodJet of BloodJet of Blood , also known as Spurt of Blood, is an extremely short play by the French Surrealist theatre practitioner, Antonin Artaud. Jet of Blood was completed in Paris, on January 17, 1925, perhaps in its entirety on that day alone...