@wikipedia

Synonym: Throttling Temperature effect = Joule–Thomson effect

Temperature change of a fluid (except ideal gas) when it is forced through a valve or percolating through porous medium while keeping it insulated so that no heat is exchanged with the environment (that is, at constant enthalpy $//<![CDATA[ \begin{array}{l}{\displaystyle H}= \rm const\end{array} //]]>$).

The value of temperature effect  $//<![CDATA[ \begin{array}{l}\Delta T\end{array} //]]>$ is proportional to pressure drop $//<![CDATA[ \begin{array}{l}\Delta P\end{array} //]]>$:

where

See also

Physics / Thermodynamics / Thermodynamic process / Adiabatic Process / Throttling process

[ Joule–Thomson coefficient ]