The IAPWS Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use

2002 ◽  
Vol 31 (2) ◽  
pp. 387-535 ◽  
Author(s):  
W. Wagner ◽  
A. Pruß
Keyword(s):  
Thermodynamic Properties ◽  
Ordinary Water ◽  
Water Substance

Assessment of the Computing Time for the IAPWS-IF97 Equations

2006 ◽  
Vol 129 (3) ◽  
pp. 885-887 ◽  
Author(s):  
Kiyoshi Miyagawa
Keyword(s):  
Thermodynamic Properties ◽  
Simple Structure ◽  
Computer Systems ◽  
Computing Time ◽  
Ordinary Water ◽  
Independent Variables ◽  
Modern Computer ◽  
Water Substance

Computing times of equations based on the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam (IAPWS-IF97) were tested. Modern computer systems are optimized for “simple” computational operations, which favors the simple structure of IAPWS-IF97. Provision of “backward equations,” which are approximation of inverse equations, is one of the features of IAPWS-IF97. The backward equations showed much shorter computing times than iterative routines, which had been used to calculate with several independent variables. IAPWS-IF97 is faster than the equations of IAPWS Formulation 1995 for the Thermodynamic properties of Ordinary Water Substance for General and Scientific Use (IAPWS-95) by factors 70 to 200 times.

New International Skeleton Tables for the Thermodynamic Properties of Ordinary Water Substance

1988 ◽  
Vol 17 (4) ◽  
pp. 1439-1540 ◽  
Author(s):  
H. Sato ◽  
M. Uematsu ◽  
K. Watanabe ◽  
A. Saul ◽  
W. Wagner
Keyword(s):  
Thermodynamic Properties ◽  
Ordinary Water ◽  
Water Substance

An Equation of State for Compressed Water from 1 to 1000 Bar and from 0°C tO 150°C

1968 ◽  
Vol 10 (4) ◽  
pp. 319-328 ◽  
Author(s):  
M. R. Gibson ◽  
E. A. Bruges
Keyword(s):  
Equation Of State ◽  
Thermodynamic Properties ◽  
Equations Of State ◽  
Dynamic Properties ◽  
Similar Type ◽  
Independent Variables ◽  
Turbine Performance ◽  
Dependent Variables ◽  
Water Turbine ◽  
Water Substance

The precision with which the thermodynamic properties of compressed water and steam are known has led, not unnaturally, to the development of equations of state suitable only for use on electronic digital computers. The equations are in the main empirical although some are highly sophisticated and lead to lengthy programs and complex sub-routines. Among such equations are those of the 1966 and 1967 Formulations of the Thermo-dynamic Properties of Ordinary Water Substance prepared by the International Formulation Committee of the International Steam Conference. The favoured form of equation has been one in which the dependent variables are enthalpy, volume and entropy and the independent variables pressure and temperature. However, this form of equation may not prove to be always the most suitable and the purpose of this paper is to describe how another type of equation, in which the dependent variable is enthalpy and the independent variables are pressure and entropy, may be established and applied. It is believed that this particular type of equation, relating as it does the three most important parameters in pump and turbine performance, has special qualities for design and efficiency calculations. By way of example the efficiency of a water turbine is evaluated according to the ‘thermodynamic method’ described by Thom (2). A concluding section outlines the further steps being taken by the authors to provide a similar type of equation over ranges of pressure and temperature up to 1000 bar and 1000°C.

Properties of Ordinary Water-Substance in all its Phases

Nature ◽  
1940 ◽  
Vol 146 (3692) ◽  
pp. 145-146 ◽  
Author(s):  
N. K. ADAM
Keyword(s):  
Ordinary Water ◽  
Water Substance

Effects of the Different Temperature Scales on the Calculation of the Thermodynamic Properties of Water Substance

1969 ◽  
Vol 11 (5) ◽  
pp. 521-525
Author(s):  
M. R. Gibson
Keyword(s):  
Thermodynamic Properties ◽  
Equations Of State ◽  
Simple Method ◽  
Temperature Scales ◽  
Thermodynamic Temperatures ◽  
Water Substance

Attention is drawn to the fact that the derivation of so-called ‘Thermodynamic Temperatures’ by the addition of the quantity, 273·15, to temperatures referred to the IPTS leads to discrepancies in the values of the thermodynamic properties calculated from equations of state by means of the thermodynamic relations. These differences are shown to be significant when compared with the tolerances in the 1963 International Skeleton Tables and a simple method of avoiding this error is described.

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