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 |
|---|---|
| g1 | Gibbs function for region 1: g(p,T) |
| g2 | Gibbs function for region 2: g(p,T) |
| g2metastable | Gibbs function for metastable part of region 2: g(p,T) |
| f3 | Helmholtz function for region 3: f(d,T) |
| g5 | base function for region 5: g(p,T) |
| gibbs | Gibbs function for region 1, 2 or 5: g(p,T,region) |
| g1pitau | derivative of g wrt pi and tau |
| g2pitau | derivative of g wrt pi and tau |
| g5pitau | derivative of g wrt pi and tau |
| f3deltatau | 1st derivatives of f wrt delta and tau |
| tph1 | inverse function for region 1: T(p,h) |
| tps1 | inverse function for region 1: T(p,s) |
| tph2 | reverse function for region 2: T(p,h) |
| tps2a | reverse function for region 2a: T(p,s) |
| tps2b | reverse function for region 2b: T(p,s) |
| tps2c | reverse function for region 2c: T(p,s) |
| tps2 | reverse function for region 2: T(p,s) |
| tsat | region 4 saturation temperature as a function of pressure |
| dtsatofp | derivative of saturation temperature w.r.t. pressure |
| tsat_der | derivative function for tsat |
| psat | region 4 saturation pressure as a functionx of temperature |
| dptofT | derivative of pressure wrt temperature along the saturation pressure curve |
| d2ptofT | Second derivative of pressure wrt temperature along the saturation pressure curve |
| psat_der | derivative function for psat |
| p1_hs | pressure as a function of ehtnalpy and entropy in region 1 |
| h2ab_s | boundary between regions 2a and 2b |
| p2a_hs | pressure as a function of enthalpy and entropy in subregion 2a |
| p2b_hs | pressure as a function of enthalpy and entropy in subregion 2a |
| p2c_hs | pressure as a function of enthalpy and entropy in subregion 2c |
| h3ab_p | ergion 3 a b boundary for pressure/enthalpy |
| T3a_ph | Region 3 a: inverse function T(p,h) |
| T3b_ph | Region 3 b: inverse function T(p,h) |
| v3a_ph | Region 3 a: inverse function v(p,h) |
| v3b_ph | Region 3 b: inverse function v(p,h) |
| T3a_ps | Region 3 a: inverse function T(p,s) |
| T3b_ps | Region 3 b: inverse function T(p,s) |
| v3a_ps | Region 3 a: inverse function v(p,s) |
| v3b_ps | Region 3 b: inverse function v(p,s) |
| g1L3 | base function for region 1 with 3rd derivatives for sensitivities: g(p,T) |
| g2L3 | base function for region 2 with 3rd derivatives for sensitivities: g(p,T) |
| f3L3 | Helmholtz function for region 3: f(d,T), including 3rd derivatives |
| g5L3 | base function for region 5: g(p,T), including 3rd derivatives |