CAPE-OPEN

In Thermo 1.1, the function "SetPresentPhases" has one parameter "phaseStatus", it's a enumeration including "Cape_UnknownPhaseStatus", "Cape_AtEquilibrium" & "Cape_Estimates".

"Cape_UnknownPhaseStatus" and "Cape_AtEquilibrium" is very easy for me to understand, but the "Cape_Estimates" makes me puzzled.

What's the exact meaning of it? Is it to notify the material object that the material object needs to call Equilibrium Calculation? Or the material object is maybe at equilibrium?

Phases that are present before an equilibrium calculation can have CAPE_ESTIMATE or CAPE_UNKNOWNPHASESTATUS status. The first indicates that pressure, temperature, composition and phase fraction for that phase can potentially be used as an initial guess for this phase for the equilibrium calculation. Presumably if a full estimate is present (of the entire phase equilibrium) the phases that have been set as estimate have phase fractions that add up to unity.

For an equilibrium server it is optional to use the estimates, it may take advantage of it, or it may simply use its internal initial estimate for the phase equilibrium.

The idea is that the information present at some iteration for example (e.g. in solving a recycle of a flowsheet) may be close to what is expected for the next iteration. In this case the software component requesting the phase equilibrium (e.g. the PME, or a unit operation) may flag the existing phase equilibrium on the MO as an initial guess for the current equilibrium calculation

Jasper, I have another question.

in Thermo 1.1, temperature, pressure, totalFlow & fraction can be achieved from material object by "GetOverallProp", but enthalpy is different,it needs to call "CalcSinglePhaseProp" and then "GetSinglePhaseProp", and at the end add all the single-phase-enthalpy to get the overall-enthalpy.

So, I want to know which properties can be achieved through "GetOverallProp", and which properties need to call "CalcSinglePhaseProp" & "GetSinglePhaseProp"?

Thank you!

Properties that are always available from an MO without calculation are temperature, pressure, fraction and phase fraction.

For a unit operation, also flow and totalFlow.

Note that if your material object is the feed of a unit operation, you may not modify it. So to get overall enthalpy, first make a duplicate, and then do the single phase enthalpy calculations. In 1.1 this requires 2 calls: CreateMaterial and CopyFromMaterial.

Thank you Jasper for your comprehensive response.