showed that passing gas through a throttled orifice
letting it expand
causes it to cool.
Specifically, we are not accelerating the gas
and we insulate the orifice to avoid exchanging heat.
Purpose
To move heat
from a cold place
to a warm place
for refrigeration
heating
and liquifying gases
Enthalpy
The energy in a system
equal to its internal energy plus
the product of pressure and volume
measured by the joule.
Orifice
Throttle valve
or porous plug
irreversible
aperture
a passageway
that gins up the cycle.
Joule-Thomson expansion converts kinetic energy to potential energy.
It does no work.
An alternative is a turbine, which in doing work removes energy from the gas.
Joule-Thomson expansion converts kinetic energy to potential energy. It does no work. An alternative is a turbine, which in doing work removes energy from the gas.
See also in The book of science:
Readings on wikipedia: