P-08 · SEE 352

Thermophysical Property Calculator

Fix any two independent properties and read off the rest, run through real CoolProp, so the numbers match PropsSI.

Code: 08
Course: SEE 352 — Applied Thermodynamics and Energy Conversion
Date: Summer 2026

loading CoolProp…

State

Fluid

Known 1

Known 2

Properties

Waiting on CoolProp — results will appear here once it's ready.

Notes

Everything is per unit mass. Enthalpy, entropy and specific heats are kJ/kg based.
The two boxes are independent — pick any two properties, in either order, the way the state postulate lets you. For the pure fluids (water and the refrigerants) every independent pair resolves: CoolProp ships a direct solver for some, and the rest (T&h, s&x, …) are found by a short pressure search that is checked back against CoolProp, so the numbers still match PropsSI. When two properties do not actually fix the state — temperature and enthalpy hardly change with pressure in a liquid, so they are not independent there — it says so rather than returning a shaky number.
Reference states differ between fluids — water uses the IAPWS triple-point reference, the refrigerants use the IIR one. Compare differences within a fluid, not absolute values across fluids.
The glycol mix is PG25 — 25 % propylene glycol by volume, the standard data-centre secondary-loop coolant. Watch the basis: CoolProp wants a mass fraction, so this is entered as INCOMP::MPG[0.257]. Taking PG at 1.036 g/cm³ and water at 0.9982 g/cm³ at 20 °C, 0.25 by volume is 0.257 by mass. Using 0.25 directly would put viscosity out by about 3 %.
That mix is an incompressible brine, not a pure fluid: its density, internal energy and entropy depend on temperature alone, and only enthalpy also carries pressure. So its state is fixed by just three pairs — T&P, P&h, or P&s — and with no vapour phase it has no quality or speed of sound. Ask for anything else and it explains why. Its enthalpy and entropy use CoolProp's own reference and go negative; only differences mean anything.
Air here is dry air — CoolProp's Air is the Lemmon (2000) dry-air equation, 28.966 g/mol, with no water vapour. Moist air needs HAPropsSI, which this page does not cover. Its critical temperature is 132.5 K, so at room conditions air is supercritical and quality is undefined.
A dash means CoolProp declined that property for this state, not zero — quality outside the dome, for instance.