A new method for deriving the Joule-Thomson coefficient of gaseous fluids from speed-of-sound measurements

A new method for the calculation of the Joule-Thomson coefficient of gaseous fluids from the speed of sound is proposed. It is based on the numerical integration of differential equations connecting the speed of sound with other thermodynamic properties. The method requires initial values of the density and the specific heat capacity at a constant pressure and at a single temperature in the pressure range of interest. It is tested by deriving the Joule-Thomson coefficient of the following gaseous fluids: argon in the temperatures between 200 and 300 K, and in the pressure range from 2 to 10 MPa; nitrogen in the temperatures between 200 and 300 K, and in the pressure range from 2 to 10 MPa; oxygen in the temperatures between 250 and 350 K, and in the pressure range from 2 to 10 MPa; methane in the temperatures between 250 and 350 K, and in the pressure range from 2 to 10 MPa. Estimated absolute average deviation (AAD) between calculated and reference values of the Joule-Thomson coefficients for argon, nitrogen, oxygen and methane are 0.2, 0.4, 0.1 and 0.7%, respectively.