Mastering Ees |link| Jun 2026
| Function | Syntax Example | What it returns | | :--- | :--- | :--- | | | T = Temperature(Steam, P=P1, s=s1) | T in °C or K | | Pressure | P = Pressure(R134a, T=T1, h=h1) | P in kPa | | Enthalpy | h = Enthalpy(Steam, T=T1, x=1) | Saturated vapor enthalpy | | Entropy | s = Entropy(Steam, P=P1, T=T1) | Entropy value | | Specific Volume | v = Volume(Steam, T=T1, P=P1) | m³/kg | | Quality | x = Quality(Steam, h=h_mix, P=P_sat) | 0 to 1 |
| Pitfall | Master’s fix | |---------|---------------| | “Iteration did not converge” | Supply better initial guesses (use Guesses or solve a simpler case first) | | “Negative absolute temperature” | Check sign of work/heat terms; enforce T > 0 as an inequality | | “Log of negative number” | Use max(1e-6, x) for arguments; or restrict domain via $IF | | Overwriting built-in functions | Never name a variable sin , log , enthalpy — EES will get confused | | Slow solve with many parametric runs | Use Array Operation»Parametric»Inline for speed; avoid Duplicate inside tables | Mastering EES
For iterative guess-and-check algorithms (like shock tubes or compressible flow), you can use: | Function | Syntax Example | What it
Use Copy to Clipboard and paste directly into LaTeX or Word. Avoid using the built-in save as JPG (it’s low resolution). enforce T >
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