with the rest of Cantera
Added an analytical derivative for dpdT for the water object.
Started adding states for the water object that refer to unstable conditions
within the spinodal curve.
of standard states and the specification of activities independent of
each other.
PDSS Behavior
-------------------------
PDSS is an object that carries out and reports on the evaluation
of the pressure dependent standard state of a single species in a mixture.
VPSSMgr Point of View
--------------------------------------
This is the calculator for the standard states.
From The Point of View of the ThermoPhase Function
---------------------------------------------------------
At the VPStandardStateTP object, the ThermoPhase object is enriched to
include a new object called VPSSMgr. VPSSMgr is
a base class that is responsible for calculating the standard states
of all of the species in the mixture. It is analogous to the
SpeciesThermo virtual base class, which handles all of the reference
state calculations for a class. The VPSSMgr class
usurps all calculations.
There are PDSS objects for each species.
VPStandardStateTP contains a vector of pointers to PDSS, of length
nSpecies in the phase. It owns the list.
VPSSMgr also contains the same vector of pointers to PDSS, of length
nSpecies in the phase. VPSSMgr is a methods class. It
organizes how to calculate the SS values efficiently. It may also have
specific rules for how to handle the pressure dependence (i.e., there
will be a specific class for ideal gases).
The VPSSMgr organizes when to update the internal states of
the PDSS objects.
The determination of which VPSSMgr virtual class to use with
which phase is determined by the phase itself. It know which method to
use.
setState Treatment with Temperature and Pressure
------------------------------------------------------
The VPStandardStateTP object always has the current value of T and P
held within it. It determines when T and P have changed. If it determines
that T or P has changed, it calls VPSSMgr so that VPSSMgr
may update its internal states.
VPSSMgr contains the current T and P, also, separately.
If it determines that T or P has changed, it recalculates its own internal state.
PDSS Object point of View
-----------------------------------------
During the evaluation of the phase thermodynamics, the PDSS object
may be called to evaluate the (T,P) Standard State and RefState information.
The PDSS object may or may not own the reference state calculation. If
it doesn't own the calculation, the ThermoPhase object owns the
calculation through its m_spthermo object. Then the PDSS objects
uses pointers into the m_spthermo object to satisfy its requirement
to supply (T,P) ss information. It may own or surplant the reference
state calculation. For example, for waterPDSS, there is no specific reference
state calculation, since the regular temperature polynomial process
is ignored (except to set the basis state). The reference state functions
are evaluated the same as other standard state functions.
If PDSS owns the calculation of the reference state thermo, then the
m_spthermo pointer within the PDSS object is zero. It does it's own
reference state calculation.
If PDSS uses the SpeciesThermo object to calculate the reference
state, it needs to know whether the SpeciesThermo object calculations
are current. It checks this. If it is, then it retrieves the result from
storage in VPSSMgr object. If it isn't, then it recalculates the results.
PDSS has its own storage for the current state of T and P.
