Equation of state for fluid alkali metals: Binodal

Abstract

The three-parameter generalized van der Waals equation of state Ibr liquids and gases is analyzed. This equation ccmtains the generalized expression a l'" Ibr the molecular pressure: here tile parameter n takes into account the specilicity of intermolecular anractivc Ibrces for various substances. The equation is presented in tile reduced Ibrm. from which follows tile single-parameter law of corresponding states with the thennodynanfic similarity parameter n. 11 is established lhal Ior alkali metals tile value of tile parameter n is the same and does not depend on temperature substantially. From tile given generalized equation, the expressions for the bmodal (equilibrium curve of tile liqtfid and vapor phases) are obtained. For cesium, rubidium, and potassiunl, tile temperature dependence of density is c;,Iculated over tile temperature range from their melting point to tile critical point: tile resuhs of tile calculations agree with experinlental data. It is established that for alkali metals, the law of rectilinear diameter breaks down m the vicinity of the critical point.

Generalized van der Waals equation of state for in-line use in hydrodynamic codes

“…The best-fit values of n, quoted in Ref. [7] for alkali metals, nicely fall in this range. Note that, when the goal is to improve the adequacy of hydrodynamic modeling, determination of n from the experimental values of Λ appears more appropriate than from the values of Z cr because a more adequate target reaction to the external energy deposition can be expected in this case -although both criteria usually yield close results.…”

“…In literature one encounters a number of different analytic equations of state called generalized van der Waals EOS [5,6,7,8,9]. Here we consider one of them, borrowed from Refs.…”

“…Here we consider one of them, borrowed from Refs. [10,11,7] and dubbed GWEOS everywhere below, which has the same simple functional form as the original van der Waals EOS but includes one more free dimensionless parameter, namely, the power exponent n > 1 in the attractive-forces correction [see Eqs. (2.3) and (2.4) below]; the original van der Waals EOS is then recovered by setting n = 2.…”

Correlations of supercritical temperature of fluid alkali metals

“…The parameter n of the generalised van der Waals equation of state was determined [38] through experimental data on liquid density and heat of evaporation at melting point [45,46] and on critical temperature [4] for the fluid alkali metals. The values of the parameter n are presented in Table 1.…”

Thermophysical Properties of Metastable Helium-3 and Helium-4

“…Many modifications of the known equations of state have been proposed [1][2][3][4][5][6][7] to improve the accuracy. These modifications result in the generalization of the known equations of state.…”