Force the phase. ThermodynamicData for saturated liquid *and* vapor.

Questions
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1

This returns the density of saturated liquid 958.367 kg/m3:

ThermodynamicData["Water", "Density", {"Pressure" -> Quantity[1, "Atmosphere"], 
"Temperature" -> Quantity[ThermodynamicData["Water","LiquidVaporPhaseBoundary", 
{"Pressure" -> Quantity[1, "Atmosphere"]}][[1]], "Kelvin"]}]

Other than doing something ugly like this

ThermodynamicData["Water", "Density", {"Pressure" ->Quantity[1, "Atmosphere"], 
"Temperature" -> Quantity[ThermodynamicData["Water","LiquidVaporPhaseBoundary", 
{"Pressure" -> Quantity[1.001, "Atmosphere"]}][[1]], "Kelvin"]}]

how can I get the density of saturated vapor 958.3675 kg/m3?

Thanks.

2

Mathematica should allow the users to select the phase directly. Any material can exists as either liquid or vapor at the same temperature. HVAC analysis require you to compare enthalpy of liquid and vapor at the same temperature.

Matlab packages does this with explicit selection of phase. For example, XSteam, package gives entropy based on temperature and phase in saturation.

XSteam(‘sV_T’, TemperatureInCentigrade )
XSteam(‘sL_T’, TemperatureInCentigrade )

3

It’s now 2024. Any changes in Mathematica that address this important question?

4

Some (re)reading of the documentation suggests that

ThermodynamicData["Water", "InternalEnergy", {"Pressure" -> 
   Quantity[0.6*10^6, "Pascals"], "Quality" -> 0}]

works. I specify 0 for saturated liquid and 1 for saturated vapor.

Does that make sense? My answers check with Reynolds and Perkins (2nd edition SI) on page 108.

5

CleanShot2024-08-22at14.27.48@2x.jpg
CleanShot2024-08-22at14.27.48@2x.jpg1426×808 101 KB

6

A blast from the past.

FWIW, Paul’s suggested form of ThermodynamicData does not work in Mathematica v11.3, which is what I currently have. (Upgrades became too expensive.) Mathematica returns “ThermodynamicData::para: Parameter list includes parameters other than Pressure and Temperature.”

Glad to hear Wolfram has since provided this functionality to ThermodynamicData.

Regards to all.

Glenn