JSteam Toolbox Naming Conventions
All functions within the toolbox are named as per the thermodynamic or transport property that they require/calculate as per the below table:
| Cp | Isobaric Heat Capacity | H | Enthalpy | Q | Duty / Power |
| Cv | Isochoric Heat Capacity | S | Entropy | V | Volume |
| U | Viscosity | T | Temperature | X | Quality (Vapor Fraction) |
| K | Thermal Conductivity | P | Pressure | M | Mass/Mole Flow |
| c | Component (Pure Fluid) | m | Mixture (Composition) |
Thermodynamic and transport functions are named using the following strategy:
| H | P | T |
| Output | Input 1 | Input 2 |
such as HPT calculates enthalpy (H), given pressure (P) and temperature (T) for Water/Steam using IAPWS IF-97, or:
| H | c | P | T |
| Output | Component | Input 1 | Input 2 |
| H | m | P | T |
| Output | Mixture | Input 1 | Input 2 |
HcPT calculates enthalpy given a component (fluid) name, pressure, and temperature, using REFPROP. Equally, HmPT calculates enthalpy given a mixture (from a mixture specification), pressure and temperature.
See the MEX Interface Guide for how the above names are used to compute thermodynamic, transport and unit operation functions.
IAPWS-97 vs REFPROP
JSteam contains two thermodynamic packages depending on type of function call used.
IAPWS-97
If you only want to compute thermodynamic or transport properties of water or steam, and favour computational speed over accuracy (which for virtually all industrial cases is perfectly adequate, the accuracy is still really good), then JSteam uses the IAPWS 1997 Industrial Formulation. This is automatically used when the user calls a function without a component or mixture specified (i.e. it defaults to water). For example: HPT(1,100) computes the Enthalpy of Water/Steam at 1 bar, 100 C (unit set dependent).
REFPROP
If you want to compute properties of any other fluid (or mixture) supported by JSteam, or if you want high accuracy water/steam computations, then JSteam utilizes REFPROP. This is the reference database for high accuracy thermodynamic and transport property computations, and is automatically used when the user calls a function with a component or mixture specified. For example: HcPT('methane',1,100) computes the Enthalpy of Methane at 1 bar, 100 C (unit set dependent).