THE THERMODYNAMIC STATE VALUES OF WATER A ND STEAM AND THEIR PARTIAL DERIVATIONS IN VARIOUS FORMS OF REPRESENTATION

The article gives a short survey on the numerical calculation of the t hermodynamic state values and their partial derivations for water and steam. The basis for this is the ''IAPS Formulation 1984 for the Therm odynamic Properties of Ordinary Water Substance for Scientific and Gen eral Use'', which at present is the best account of the thermodynamic properties of water and steam. This formulation is based on the Hemhol tz-function. dependent on density and temperature. Besides this form o f presentation, a calculation procedure is here discussed, which enabl es the determination of the thermodynamic properties, also as function of temperature and pressure, as well as of pressure and density.