Description of functions for calculation of properties of water and water steam in the WaterSteamPro package
All WaterSteamPro functions receive arguments and return answers in dimensions of the SI-system. The program Mathcad Professional of the MathSoft, Inc company allows additional facilities for operation with dimensional values.
The most of the functions (except some system functions) takes arguments and returns answers in double type (a real number with double precision).
In the case of an error, all functions return the value of -1 (minus one). The function "wspGETLASTERROR()" allows analysis of an error code. An error code is saved until another call of a "WaterSteamPro" function, except for system functions.
The "WaterSteamPro" package presents unified function names (they have identical names in different programs) which are generated according to the following rules:
- A name starts with the prefix "wsp" (in small letters);
- Then comes a descriptor of the sought quantity the function returns. For example, for specific enthalpy it is "H" (in capitals);
- The next component - is a descriptor of water/water steam area and conditions. For example, for water in the saturation line it is - "SW" (from "Saturated Water"). Names of generalized functions (for example, specific volume as a function of pressure and temperature) do not contain this component.
- The name is completed by argument descriptors. Thus, for specific volume as a function of pressure, temperature and degree of dryness it is "PTX" - from "P" - "Pressure"; "T" - "Temperature"; "X" - "degree of dryness (X)".
String descriptors of quantities and their dimensions in the SI-system are presented below:
- Pressure: "Pressure" - "P", [Pa];
- Temperature: "Temperature" - "T", [K];
- Specific volume: "specific Volume" - "V", [m3/kg];
- Specific internal energy: "specific internal energy (U) " - "U", [J/kg];
- Specific entropy: "specific entropy (S) " - "S", [J/(kg·K)];
- Specific enthalpy: " specific enthalpy (H) " - "H", [J/kg];
- Specific heat capacity at constant pressure: "specific heat Capacity at constant Pressure" - "CP", [J/(kg·K)];
- Specific heat capacity at constant volume: "specific heat Capacity at constant Volume" - "CV", [J/(kg·K)];
- Sound velocity: "sound velocity (W) " - "W", [m/s];
- Density: "density (R)" - "R", [kg/m3];
- Specific evaporation heat: "specific evaporation heat (R) " - "R", [J/kg];
- Thermal conductivity: "THERMal CONDuctivity" - "THERMCOND", [W/(m·K)];
- Dynamic viscosity: "DYNamic VIScosity" - "DYNVIS", [Pa·sec] = [kg/(m·sec)];
- Kinematic viscosity: "KINematic VIScosity" - "KINVIS", [m2/sec];
- Coefficient of surface tension: "SURFace TENsion" - "SURFTEN", [N/m];
- Prandtl number "PRANDTLE's number" - "PRANDTLE", [-];
- Isoentropic exponent: "isoentropic exponent (K) " - "K", [-];
- Joule-Thompson coefficient: "JOULE-THOMPSON coefficient " - "JOULETHOMPSON", [K/Pa];
Descriptors of water areas and conditions:
- Generalized functions (range of definition - is the full range) - without descriptor;
- Functions for calculation of water properties in the saturation line: "Saturation Water " - "SW";
- Functions for calculation of steam properties in the saturation line: "Saturation Steam " - "SS";
- Functions for calculation of the two-phase area properties: "Saturation" - "S";
- Functions for calculation meta-stable properties: "MetaStable" - "MS";