@wikipedia

The rate of change of temperature $\begin{array}{l}{\displaystyle T}\end{array}$ with respect to pressure $\begin{array}{l}{\displaystyle P}\end{array}$ in a throttling process:

(1)	$\begin{array}{l}\displaystyle \mu_{JT} = \left( \frac{\partial T}{\partial P} \right)_{H} = \frac{\alpha_V \cdot T - 1}{c_{vp}}\end{array}$

where

$\begin{array}{l}T\end{array}$	Temperature
$\begin{array}{l}\alpha_V\end{array}$	Thermal expansion coefficient
$\begin{array}{l}c_{vp}\end{array}$	Isobaric volumetric heat capacity

For Ideal Gas: $\begin{array}{l}\alpha_V \sim \frac{}1{T}\end{array}$ and Joule–Thomson coefficient is strictly zero: $\begin{array}{l}\mathrm{\mu_{JT}\,= 0}\end{array}$

Page tree

See also