Common function's description and areas of usage

There are functions for calculating thermodynamic properties, kinematic and dynamic viscosities, thermal conductivity, Prandtle's number for water and steam at saturation line and onephase areas, and surface tension in the WaterSteamPro.

All thermodynamic properties calculated for Formulation IF–97 [2]. All values of the thermodynamic properties of water and steam at saturation line with temperature more than 350 °C (pressure more 16,5 MPa) calculated through formulation for area 3 with values of temperature and pressure, calculated with formulation for saturation line (area 4). All thermodynamic functions involve temperature area from 0.01 to 1000 °C with pressure up to 10 ÌÏà and from 0.01 to 800 °C with pressure up to 100 MPa.

Dynamic viscosity calculated from Formulation IAPWS–85 [5], corrected for temperature scale ITS–90. And the values of density in this formulation calculate for Formulation IF–97.

The values of kinematic viscosity calculate with this formula:

ν = μ / ρ

where: μ - dynamic viscosity (from Formulation IAPWS–85), ρ - density (from Formulation IF–97).

Thermal conductivity of water and steam at saturation line calcuted from formulation IAPWS–85, recommended for industrial use [6], and corrected for temperature scale ITS–90. And the values of density in this formulation calculate for Formulation IF–97. The area of calculation is (from IAPWS): temperature from 0.01 to 800 °C for pressure to 40 MPa, from 0.01 to 650 °C for pressure from 40 to 70 MPa, from 0.01 to 500 °C for pressure from 70 to 100 MPa.

The Prandtle's number calculated as:

Pr = (μ·Cp) / λ

where: μ - dynamic viscosity (from Formulation IAPWS–85); Cp - specific isobaric heat capacity (from Formulation IF–97); λ - thermal conductivity (IAPWS formulation from 1985). The area of usage is accord to area for thermal conductivity.

Isoentropic exponent calculated as:

K = w * w / (p * v)

where: w - sound velocity; p - pressure; v - specific volume. The area of usage is accord to the areas of the IF-97.

Joule-Thompson coefficient (JT = (dt/dp)h) calculated with formulas which is specific for the each of the IF-97 area.