Y.H. Huang

Debye equation of state for fluid helium-3

An equation of state for 3He using the Helmholtz potential function has been developed. The lower limit of the equation of 0.01 K is safely above the superfluid transition at 0.0026 K. The upper limit of 60 K is approximately the upper limit of available 3He property measurements. The new state equation form is based on Debye function which goes smoothly to zero in the limit of zero temperature and reduces to the ideal gas in the limit of zero density and/or very high temperature. The equation combines (a) necessary temperature-independent compressibility terms at the lowest temperatures, (b) terms describing the linear specific heat of a Fermi fluid below 1 K, (c) terms describing the phonon excitations which begin above about 1 K, and (d) terms which attempt to fit the conventional critical point thermodynamics at 3.3157 K and 114 604 Pa. State properties, e.g., p-V-T relations, specific heats, thermal expansion, sound velocity, etc., are determined from the Helmholtz energy by standard thermodynamics. Transport properties, e.g., thermal conductivity and viscosity, are not obtained in this work.

Equation of state for fluid helium-3 based on Debye phonon model

An equation of state for He3 using the Helmholtz potential function has been developed. It is based on the Debye phonon model which goes smoothly to zero in the limit of zero temperature, and reduces to the ideal gas in the limit of zero density and/or very high temperature. The lower temperature limit of the equation 10mK is safely above the superfluid transition at 2.6mK. The upper limit of 60K is approximately the upper limit of available He3 properties measurements. The certain pressure range of validity of the equation is from about 0 to the melting pressure or 15MPa. State properties are determined from the Helmholtz energy by standard thermodynamics.

Debye Equation of State for 3HE from 0.01 to 20 K

An equation of state for 3He using the Helmholtz potential function has been obtained from available published experimental data. The lower limit of the equation 0.01 K is safely above the superfluid transition at 0.0026K. The upper limit of 20 K is approximately the upper limit of available 3He properties measurements. The new state equation form is based on Debye functions which go smoothly to zero in the limit of zero temperature, and reduce to the ideal gas in the limit of zero density and/or very high temperature. The equation combines (a) necessary temperature‐independent compressibility terms at the lowest temperatures, (b) terms describing the linear specific heat of a Fermi fluid below 1 K, (c) terms describing the phonon excitations which begin above about 1 K, and (d) terms which attempt to fit the conventional critical point thermodynamics at 3.3157 K and 114604 Pa. State properties, e.g., p‐V‐T relations, specific heats, thermal expansion, sound velocity, etc., are determined from the Helmhol...

Chapter 206 – A density equation for saturated helium-3*

Publisher Summary This chapter introduces the work of collecting experimental data and building the density equation of saturated vapor and liquid 3 He. An accuracy satisfying density equation of saturated vapor and liquid 3 He is obtained by nonlinear regression based on experimental data collected after a thorough survey of literatures. This equation not only can be used to calculate saturated density of 3 He independently, but also is to be of great significance in building the equation of state for 3 He in both gas and liquid regions. For a better understanding of the equation, the saturated density curves of 3 He and 4 He are compared. The average relative error of calculated values from experimental values is 0.360%, while the maximum relative error is 1.995%. There are only 16 points out of 205 with the relative error above 1%. The similarity of saturated density curves of 3 He and 4 He suggests a possibility of scaling.