Joule Inversion Temperatures for Some Simple Real Gases

Abstract

Abstract:In the present work we calculate inversion temperatures T i , for some simple real gases (He, Ne, Ar, Kr and H 2 ) in the case of a Joule expansion; that is, a free adiabatic expansion. These calculations are made by means of an intermolecular potential of the Lennard-Jones type (12, 6), slightly modified by using a Jagla linear ramp in the repulsive part of the potential. For the Helium we find a T i in agreement with both previous calculations published by other authors and with experimental results. For Ne and Ar our results are also within the interval of values previously reported, and for Kr we also obtain a very high inversion temperature as some other authors. However, for H 2 we find a T i approximately twice to big than its estimated experimental value. This last calculation is corrected if we use a short ranged Lennard-Jones potential of the type (24, 12), obtaining a result in good agreement with the recognized experimental value.

Improving Students’ Understanding of the Connections between the Concepts of Real-Gas Mixtures, Gas Ideal-Solutions, and Perfect-Gas Mixtures

“…At temperatures above T B , the second virial coefficient is positive and increases slowly. As a noticeable feature, experimental evidence has been given for some fluids that the second virial coefficient can reach a maximum (the corresponding temperature is named inversion temperature) . At high temperature, the second virial coefficient approaches zero as described by Beattie and Stockmayer: “At the Boyle temperature and according to theory, at infinite temperature [the second virial coefficient] limit is zero” .…”

The Contribution of The Joule-Thomson Effect To Solar Coronal Heatin

“…The corresponding J-T coefficient μJT denotes (δT/δP) H where T is the change of temperature, P is the decrease in pressure and H constant enthalpy. A subsidiary issue is the extent to which throttling -or, as Thomson & Joule (1852) put it, 'rushing through small apertures' -is critical to the effect: some sources apply the name Joule-Kelvin to expansion with throttling and the name Joule to free expansion [4,5].…”