How to specify the phase in a TwoPhase Fluid

[rclUPC]

Hi, sorry, but I have not clear if it is possible to specify the phase in order to compute the properties of one of the phases in a TwoPhase fluid. For instance, for water,

from pyfluids import Fluid, FluidsList, Phases, Input
fluid = "Water"
water = PF.specify_phase(Phases.Liquid).with_state(Input.pressure(10e3),Input.enthalpy(2e5))
water.density

the result is the density for the twoPhase fluid, not for only the liquid phase.

Thank you
Robert

[portyanikhin]

Hello, Robert!

As far as I know, this method (specify_phase) is used by CoolProp to speed up calculations:
https://coolprop.sourceforge.net/coolprop/LowLevelAPI.html#imposing-the-phase-optional

In your case, CoolProp, instead of issuing any error (as it happens in other similar cases), for some reason resists and doesn't want to fix the phase. I don't know if this is a mistake, or if the CoolProp developers intended it that way. In any case, I can't influence it in any way.

In this case, I would advise you to take advantage of the properties of a saturated liquid. In my opinion, this is quite logical, since a two-phase fluid is simply a mixture of saturated liquid and saturated vapor in a certain proportion (which may change, for example, during evaporation).

from pyfluids import Fluid, FluidsList, Input

saturated_water = Fluid(FluidsList.Water).with_state(Input.pressure(10e3), Input.quality(0))
saturated_vapor = Fluid(FluidsList.Water).with_state(Input.pressure(10e3), Input.quality(1))

print(saturated_water.density) # 989.8332753648964
print(saturated_vapor.density) # 6.770413445120213

I hope it helped in some way