D2O, Computation of Thermodynamic and Transport Properties of Heavy Water

1 - Description of program or function: A computer program for the fast computation of the thermodynamic and transport properties of heavy water (D2O) at saturation, in subcooled liquid and superheated vapor states. Specific volume (or density), specific enthalpy, specific entropy, constant-pressure specific heat and temperature at saturation are calculated by a number of piecewise continuous approximation functions of (and their derivatives are calculated with respect to) pressure whereas pressure at saturation is calculated by a piecewise continuous approximation function of temperature for heavy water. Density in subcooled liquid state, specific volume in super-heated vapor state, specific enthalpy, specific entropy and constant-pressure specific heat in both of these states are calculated by some piecewise continuous approximation functions of pressure and temperature for heavy water. The correlations used in the calculation of these thermodynamic properties of heavy water were derived by fitting some appropriate curves to the data given in the steam tables by Hill et al (1981). The whole set of correlations and the approximation method used in their derivation are presented by Durmayaz (1997). Dynamic viscosity and thermal conductivity for heavy water are calculated as functions of temperature and density with the correlations given by Hill et al (1981), by Matsunaga and Nagashima (1983) and by Kestin et al (1984). Surface tension for heavy water is calculated as a function of temperature with the correlation given by Crabtree and Siman-Tov (1993). 2 - Methods: A group of pressure-enthalpy (P-h) pairs can be given in an input data file or assigned in the main program without knowing the state in which fluid takes place. In this case, first, the enthalpies at saturation corresponding to the given pressure are computed. Second, the state is determined by comparing the given enthalpy to the saturation enthalpies. Then, the properties are computed. Program D2O can also be linked as a subroutine of another main program. In this case, any thermodynamic property at saturation can be computed directly as a function of saturation pressure as well as saturation pressure is determined directly as a function of saturation temperature. Similarly, if a P-h pair is known in subcooled liquid or superheated vapor state, any thermodynamic or transport property can be computed directly. If a pressure-temperature (P-T) pair is known in subcooled liquid or superheated vapor state, enthalpy can also be computed directly. 3 - Restrictions on the complexity of the problem: The range of use and the maximum error for each correlation of the thermodynamic properties of heavy water are presented by Durmayaz (1997), and are also given in the statements in the beginning of each function subprogram for each correlation