Jet
- See also jet (lignite), JET (Japanese English Teacher) and Jet, a rock band from Melbourne, Australia, Blue jet, a form of upper atmospheric lightning, Jet (comic), JET (Joint European Torus)
A jet is a stream of fluid produced by discharge through an orifice into free space.
Since gases are compressible fluids, the velocity attained by a jet of gas cannot be determined by Bernoulli's principle. Instead, if one uses adiabatic expansion from P1 to P2 in a properly shaped nozzle, the ideal velocity of a gas jet is:
- <math>v=8\sqrt{(RT_1/z) (1-(P_2/P_1)^z)} <math>
where R and z are characteristics of the gas, R being the common gas constant and z being (cp − cv)/cp, where the cs are the specific heat at constant pressure and constant volume, respectively.
z = 0.286 for air under 500 °C.
z = 0.23 to 0.28 for most combustion products of fuels.
T1 is the absolute temperature at pressure P1.
See jet engine and jet aircraft.
