Package BaseIF97/Basic computes the the fundamental functions for the 5 regions of the steam tables as described in the standards document IF97.pdf. The code of these functions has been generated using Mathematica and the add-on packages "Format" and "Optimize" to generate highly efficient, expression-optimized C-code from a symbolic representation of the thermodynamic functions. The C-code has than been transformed into Modelica code. An important feature of this optimization was to simultaneously optimize the functions and the directional derivatives because they share many common subexpressions.
| Name | Description |
|---|---|
| Gibbs function for region 1: g(p,T) | |
| Gibbs function for region 2: g(p,T) | |
| Gibbs function for metastable part of region 2: g(p,T) | |
| Helmholtz function for region 3: f(d,T) | |
| base function for region 5: g(p,T) | |
| Gibbs function for region 1, 2 or 5: g(p,T,region) | |
| derivative of g wrt pi and tau | |
| derivative of g wrt pi and tau | |
| derivative of g wrt pi and tau | |
| 1st derivatives of f wrt delta and tau | |
| inverse function for region 1: T(p,h) | |
| inverse function for region 1: T(p,s) | |
| reverse function for region 2: T(p,h) | |
| reverse function for region 2a: T(p,s) | |
| reverse function for region 2b: T(p,s) | |
| reverse function for region 2c: T(p,s) | |
| reverse function for region 2: T(p,s) | |
| region 4 saturation temperature as a function of pressure | |
| derivative of saturation temperature w.r.t. pressure | |
| derivative function for tsat | |
| region 4 saturation pressure as a functionx of temperature | |
| derivative of pressure wrt temperature along the saturation pressure curve | |
| Second derivative of pressure wrt temperature along the saturation pressure curve | |
| derivative function for psat | |
| pressure as a function of ehtnalpy and entropy in region 1 | |
| boundary between regions 2a and 2b | |
| pressure as a function of enthalpy and entropy in subregion 2a | |
| pressure as a function of enthalpy and entropy in subregion 2a | |
| pressure as a function of enthalpy and entropy in subregion 2c | |
| ergion 3 a b boundary for pressure/enthalpy | |
| Region 3 a: inverse function T(p,h) | |
| Region 3 b: inverse function T(p,h) | |
| Region 3 a: inverse function v(p,h) | |
| Region 3 b: inverse function v(p,h) | |
| Region 3 a: inverse function T(p,s) | |
| Region 3 b: inverse function T(p,s) | |
| Region 3 a: inverse function v(p,s) | |
| Region 3 b: inverse function v(p,s) | |
| base function for region 1 with 3rd derivatives for sensitivities: g(p,T) | |
| base function for region 2 with 3rd derivatives for sensitivities: g(p,T) | |
| Helmholtz function for region 3: f(d,T), including 3rd derivatives | |
| base function for region 5: g(p,T), including 3rd derivatives |