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[Cython] Allow setting state while holding specific properties constant

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The value "None" is used to indicate the property or properties being held
constant.
This commit is contained in:
Ray Speth 2013-05-31 15:56:36 +00:00
parent 02112c7cde
commit e667978655
3 changed files with 104 additions and 20 deletions
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10
doc/sphinx/cython/tutorial.rst
View file

@ -276,6 +276,16 @@ Or, to set all the mass fractions to equal values::
>>> gas1.Y = np.ones(53)
When setting the state, you can control what properties are held constant by
passing the special value `None` to the property setter. For example, to
change the specific volume to 2.1 m^3/kg while holding entropy constant::
>>> gas.SV = None, 2.1
Or to set the mass fractions while holding temperature and pressure constant::
>>> gas.TPX = None, None, 'CH4:1.0, O2:0.5'
Working With Mechanism Files
----------------------------

34
interfaces/cython/cantera/test/test_thermo.py
View file

@ -168,6 +168,40 @@ class TestThermoPhase(utilities.CanteraTest):
self.check_setters(T1 = 750.0, rho1 = 0.02,
Y1 = [0.2, 0.1, 0.0, 0.3, 0.1, 0.0, 0.0, 0.2, 0.1])
def test_setters_hold_constant(self):
props = ('T','P','s','h','u','v','X','Y')
pairs = [('TP', 'T', 'P'), ('SP', 's', 'P'),
('UV', 'u', 'v')]
self.phase.TDX = 1000, 1.5, 'H2O:0.1, O2:0.95, AR:3.0'
values = {}
for p in props:
values[p] = getattr(self.phase, p)
for pair, first, second in pairs:
self.phase.TDX = 500, 2.5, 'H2:0.1, O2:1.0, AR:3.0'
first_val = getattr(self.phase, first)
second_val = getattr(self.phase, second)
setattr(self.phase, pair, (values[first], None))
self.assertNear(getattr(self.phase, first), values[first])
self.assertNear(getattr(self.phase, second), second_val)
self.phase.TDX = 500, 2.5, 'H2:0.1, O2:1.0, AR:3.0'
setattr(self.phase, pair, (None, values[second]))
self.assertNear(getattr(self.phase, first), first_val)
self.assertNear(getattr(self.phase, second), values[second])
self.phase.TDX = 500, 2.5, 'H2:0.1, O2:1.0, AR:3.0'
setattr(self.phase, pair + 'X', (None, None, values['X']))
self.assertNear(getattr(self.phase, first), first_val)
self.assertNear(getattr(self.phase, second), second_val)
self.phase.TDX = 500, 2.5, 'H2:0.1, O2:1.0, AR:3.0'
setattr(self.phase, pair + 'Y', (None, None, values['Y']))
self.assertNear(getattr(self.phase, first), first_val)
self.assertNear(getattr(self.phase, second), second_val)
def test_setter_errors(self):
with self.assertRaises(Exception):
self.phase.TD = 400

80
interfaces/cython/cantera/thermo.pyx
View file

@ -440,7 +440,9 @@ cdef class ThermoPhase(_SolutionBase):
return self.T, self.density
def __set__(self, values):
assert len(values) == 2
self.thermo.setState_TR(values[0], values[1] * self._mass_factor())
T = values[0] if values[0] is not None else self.T
D = values[1] if values[1] is not None else self.density
self.thermo.setState_TR(T, D * self._mass_factor())
property TDX:
"""
@ -451,8 +453,10 @@ cdef class ThermoPhase(_SolutionBase):
return self.T, self.density, self.X
def __set__(self, values):
assert len(values) == 3
T = values[0] if values[0] is not None else self.T
D = values[1] if values[1] is not None else self.density
self.X = values[2]
self.TD = values[:2]
self.thermo.setState_TR(T, D * self._mass_factor())
property TDY:
"""
@ -463,8 +467,10 @@ cdef class ThermoPhase(_SolutionBase):
return self.T, self.density, self.Y
def __set__(self, values):
assert len(values) == 3
T = values[0] if values[0] is not None else self.T
D = values[1] if values[1] is not None else self.density
self.Y = values[2]
self.TD = values[:2]
self.thermo.setState_TR(T, D * self._mass_factor())
property TP:
"""Get/Set temperature [K] and pressure [Pa]."""
@ -472,7 +478,9 @@ cdef class ThermoPhase(_SolutionBase):
return self.T, self.P
def __set__(self, values):
assert len(values) == 2
self.thermo.setState_TP(values[0], values[1])
T = values[0] if values[0] is not None else self.T
P = values[1] if values[1] is not None else self.P
self.thermo.setState_TP(T, P)
property TPX:
"""Get/Set temperature [K], pressure [Pa], and mole fractions."""
@ -480,8 +488,10 @@ cdef class ThermoPhase(_SolutionBase):
return self.T, self.P, self.X
def __set__(self, values):
assert len(values) == 3
T = values[0] if values[0] is not None else self.T
P = values[1] if values[1] is not None else self.P
self.X = values[2]
self.TP = values[:2]
self.thermo.setState_TP(T, P)
property TPY:
"""Get/Set temperature [K], pressure [Pa], and mass fractions."""
@ -489,8 +499,10 @@ cdef class ThermoPhase(_SolutionBase):
return self.T, self.P, self.Y
def __set__(self, values):
assert len(values) == 3
T = values[0] if values[0] is not None else self.T
P = values[1] if values[1] is not None else self.P
self.Y = values[2]
self.TP = values[:2]
self.thermo.setState_TP(T, P)
property UV:
"""
@ -501,8 +513,10 @@ cdef class ThermoPhase(_SolutionBase):
return self.u, self.v
def __set__(self, values):
assert len(values) == 2
self.thermo.setState_UV(values[0] / self._mass_factor(),
values[1] / self._mass_factor())
U = values[0] if values[0] is not None else self.u
V = values[1] if values[1] is not None else self.v
self.thermo.setState_UV(U / self._mass_factor(),
V / self._mass_factor())
property UVX:
"""
@ -513,8 +527,11 @@ cdef class ThermoPhase(_SolutionBase):
return self.u, self.v, self.X
def __set__(self, values):
assert len(values) == 3
U = values[0] if values[0] is not None else self.u
V = values[1] if values[1] is not None else self.v
self.X = values[2]
self.UV = values[:2]
self.thermo.setState_UV(U / self._mass_factor(),
V / self._mass_factor())
property UVY:
"""
@ -525,8 +542,11 @@ cdef class ThermoPhase(_SolutionBase):
return self.u, self.v, self.Y
def __set__(self, values):
assert len(values) == 3
U = values[0] if values[0] is not None else self.u
V = values[1] if values[1] is not None else self.v
self.Y = values[2]
self.UV = values[:2]
self.thermo.setState_UV(U / self._mass_factor(),
V / self._mass_factor())
property HP:
"""Get/Set enthalpy [J/kg or J/kmol] and pressure [Pa]."""
@ -534,7 +554,9 @@ cdef class ThermoPhase(_SolutionBase):
return self.h, self.P
def __set__(self, values):
assert len(values) == 2
self.thermo.setState_HP(values[0] / self._mass_factor(), values[1])
H = values[0] if values[0] is not None else self.h
P = values[1] if values[1] is not None else self.P
self.thermo.setState_HP(H / self._mass_factor(), P)
property HPX:
"""Get/Set enthalpy [J/kg or J/kmol], pressure [Pa] and mole fractions."""
@ -542,8 +564,10 @@ cdef class ThermoPhase(_SolutionBase):
return self.h, self.P, self.X
def __set__(self, values):
assert len(values) == 3
H = values[0] if values[0] is not None else self.h
P = values[1] if values[1] is not None else self.P
self.X = values[2]
self.HP = values[:2]
self.thermo.setState_HP(H / self._mass_factor(), P)
property HPY:
"""Get/Set enthalpy [J/kg or J/kmol], pressure [Pa] and mass fractions."""
@ -551,8 +575,10 @@ cdef class ThermoPhase(_SolutionBase):
return self.h, self.P, self.Y
def __set__(self, values):
assert len(values) == 3
H = values[0] if values[0] is not None else self.h
P = values[1] if values[1] is not None else self.P
self.Y = values[2]
self.HP = values[:2]
self.thermo.setState_HP(H / self._mass_factor(), P)
property SP:
"""Get/Set entropy [J/kg/K or J/kmol/K] and pressure [Pa]."""
@ -560,7 +586,9 @@ cdef class ThermoPhase(_SolutionBase):
return self.s, self.P
def __set__(self, values):
assert len(values) == 2
self.thermo.setState_SP(values[0] / self._mass_factor(), values[1])
S = values[0] if values[0] is not None else self.s
P = values[1] if values[1] is not None else self.P
self.thermo.setState_SP(S / self._mass_factor(), P)
property SPX:
"""Get/Set entropy [J/kg/K or J/kmol/K], pressure [Pa], and mole fractions."""
@ -568,8 +596,10 @@ cdef class ThermoPhase(_SolutionBase):
return self.s, self.P, self.X
def __set__(self, values):
assert len(values) == 3
S = values[0] if values[0] is not None else self.s
P = values[1] if values[1] is not None else self.P
self.X = values[2]
self.SP = values[:2]
self.thermo.setState_SP(S / self._mass_factor(), P)
property SPY:
"""Get/Set entropy [J/kg/K or J/kmol/K], pressure [Pa], and mass fractions."""
@ -577,8 +607,10 @@ cdef class ThermoPhase(_SolutionBase):
return self.s, self.P, self.Y
def __set__(self, values):
assert len(values) == 3
S = values[0] if values[0] is not None else self.s
P = values[1] if values[1] is not None else self.P
self.Y = values[2]
self.SP = values[:2]
self.thermo.setState_SP(S / self._mass_factor(), P)
property SV:
"""
@ -589,8 +621,10 @@ cdef class ThermoPhase(_SolutionBase):
return self.s, self.v
def __set__(self, values):
assert len(values) == 2
self.thermo.setState_SV(values[0] / self._mass_factor(),
values[1] / self._mass_factor())
S = values[0] if values[0] is not None else self.s
V = values[1] if values[1] is not None else self.v
self.thermo.setState_SV(S / self._mass_factor(),
V / self._mass_factor())
property SVX:
"""
@ -601,8 +635,11 @@ cdef class ThermoPhase(_SolutionBase):
return self.s, self.v, self.X
def __set__(self, values):
assert len(values) == 3
S = values[0] if values[0] is not None else self.s
V = values[1] if values[1] is not None else self.v
self.X = values[2]
self.SV = values[:2]
self.thermo.setState_SV(S / self._mass_factor(),
V / self._mass_factor())
property SVY:
"""
@ -613,8 +650,11 @@ cdef class ThermoPhase(_SolutionBase):
return self.s, self.v, self.Y
def __set__(self, values):
assert len(values) == 3
S = values[0] if values[0] is not None else self.s
V = values[1] if values[1] is not None else self.v
self.Y = values[2]
self.SV = values[:2]
self.thermo.setState_SV(S / self._mass_factor(),
V / self._mass_factor())
# partial molar / non-dimensional properties
property partial_molar_enthalpies: