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|Author(s):||V. Arp; Yonghua Huang; Ray Radebaugh; G.B. Chen;|
|Title:||THE DEBYE FLUID STATE EQUATION|
|Published:||April 02, 2007|
|Abstract:||We describe a new form of a fluid state equation, based on a conceptual extrapolation from the Debye equation for the specific heat of solid materials. The Debye characteristic temperature, theta, which is nominally a constant for solids, becomes a function of the fluid density d. Further assuming theta = c1*d^(2/3)(1 + c2*d + c3*d^2 + ...) yields the conventional fluid virial equation in the high T and low d limit for a monatomic fluid. Additional terms must be added to describe (a) compressibility of the dense subcooled fluid, and (b) properties in the near-critical range. Discussion of the Gruneisen parameter and other factors is included. This Debye fluid theory has been useful in the state equation for 3He, continuous from 0.005 K to above room temperature. The mathematical form of conventional fluid state equations precludes their use below about 1/2 of the critical temperature, or 2 K for 3He, though they might be more accurate than the Debye equations above that temperature.|
|Citation:||International Journal of Thermophysics|
|Pages:||pp. 417 - 428|
|Keywords:||Debye theory, helium isotope, specific heat, state equation|
|PDF version:||Click here to retrieve PDF version of paper (7MB)|