feedtwin.props.fluid Namespace Reference

Classes
class	Fluid

Functions
None	_validate (str name, float value)

Variables
dict	_PAIR_BY_KWARGS
dict	_PAIR_BY_ORDERED
tuple	_SNAPSHOT_PROPS = ("p", "T", "rho", "h", "s", "u", "cp", "cv", "mu", "k", "a", "Z")
dict	_STRICTLY_POSITIVE
dict	_UNIT_FRACTION = {"q": "vapour quality [-]"}
dict	_FAST_LOW = {name: 0.0 for name in (*_STRICTLY_POSITIVE, "q")}
dict	_FAST_HIGH = {"q": 1.0}
dict	_FAST_RESOLVE
	ChainEntry = str | PropertyBackend
int	_MEMO_ENTRIES = 512

Detailed Description

The caller-facing handle: a fluid you can ask for properties.

``Fluid`` is a thin thing over a *chain* of backends::

    n2 = Fluid("nitrogen")            # ["bicubic", "heos"]
    n2.get("rho", p=3.1e7, T=293.0)   # ~0.13 us, from tables
    n2.get("rho", p=5.0e9, T=293.0)   # tables refuse; the EOS answers

The chain is the whole design. "Fast where possible, exact where necessary,
measured where we have data" is a list, not a branch -- so adding a source means
adding an element, and no call site learns about it.

Threading
---------
Backends wrap mutable cursors: ``update`` moves them, ``value`` reads wherever
they were last moved. Two threads sharing one would interleave into nonsense
that never raises -- each would read the other's state point. Every backend is
therefore **thread-confined**: built per thread, on demand, and never handed
across. A ``Fluid`` is safe to share; the backends underneath it are not, and
never leave.

Function Documentation

_validate()

None feedtwin.props.fluid._validate ( str name, float value )

protected

Definition at line 110 of file fluid.py.

Referenced by feedtwin.props.fluid.Fluid._resolve(), and feedtwin.props.fluid.Fluid.accessor().

Variable Documentation

_FAST_HIGH

dict feedtwin.props.fluid._FAST_HIGH = {"q": 1.0}

protected

Definition at line 91 of file fluid.py.

_FAST_LOW

dict feedtwin.props.fluid._FAST_LOW = {name: 0.0 for name in (*_STRICTLY_POSITIVE, "q")}

protected

Definition at line 90 of file fluid.py.

_FAST_RESOLVE

dict feedtwin.props.fluid._FAST_RESOLVE

protected

Initial value:

=  {
    order: (
        pair,
        order == names,
        order[0],
        _FAST_LOW.get(order[0], -math.inf),
        _FAST_HIGH.get(order[0], math.inf),
        order[1],
        _FAST_LOW.get(order[1], -math.inf),
        _FAST_HIGH.get(order[1], math.inf),
    )
    for order, (pair, names) in _PAIR_BY_ORDERED.items()
}

Definition at line 92 of file fluid.py.

_MEMO_ENTRIES

int feedtwin.props.fluid._MEMO_ENTRIES = 512

protected

Definition at line 143 of file fluid.py.

_PAIR_BY_KWARGS

dict feedtwin.props.fluid._PAIR_BY_KWARGS

protected

Initial value:

=  {
    frozenset({"p", "T"}): (StatePair.PT, ("p", "T")),
    frozenset({"p", "h"}): (StatePair.PH, ("p", "h")),
    frozenset({"p", "s"}): (StatePair.PS, ("p", "s")),
    frozenset({"p", "q"}): (StatePair.PQ, ("p", "q")),
    frozenset({"T", "q"}): (StatePair.TQ, ("T", "q")),
    frozenset({"p", "rho"}): (StatePair.PD, ("p", "rho")),
    frozenset({"h", "s"}): (StatePair.HS, ("h", "s")),
    frozenset({"rho", "T"}): (StatePair.DT, ("rho", "T")),
    frozenset({"rho", "u"}): (StatePair.DU, ("rho", "u")),
}

Definition at line 41 of file fluid.py.

_PAIR_BY_ORDERED

dict feedtwin.props.fluid._PAIR_BY_ORDERED

protected

Initial value:

=  {
    order: entry
    for keys, entry in _PAIR_BY_KWARGS.items()
    for order in ((tuple(sorted(keys))), tuple(reversed(sorted(keys))))
}

Definition at line 59 of file fluid.py.

_SNAPSHOT_PROPS

tuple feedtwin.props.fluid._SNAPSHOT_PROPS = ("p", "T", "rho", "h", "s", "u", "cp", "cv", "mu", "k", "a", "Z")

protected

Definition at line 66 of file fluid.py.

_STRICTLY_POSITIVE

dict feedtwin.props.fluid._STRICTLY_POSITIVE

protected

Initial value:

=  {
    "p": "pressure [Pa]",
    "T": "temperature [K]",
    "rho": "density [kg/m^3]",
}

Definition at line 75 of file fluid.py.

_UNIT_FRACTION

dict feedtwin.props.fluid._UNIT_FRACTION = {"q": "vapour quality [-]"}

protected

Definition at line 81 of file fluid.py.

ChainEntry

feedtwin.props.fluid.ChainEntry = str | PropertyBackend

Definition at line 130 of file fluid.py.