'''Chemical Engineering Design Library (ChEDL). Utilities for process modeling.
Copyright (C) 2016, 207, 2018, 2019, 2020 Caleb Bell <Caleb.Andrew.Bell@gmail.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
This module contains implementations of :obj:`TDependentProperty <thermo.utils.TDependentProperty>`
representing liquid-air surface tension. A variety of estimation
and data methods are available as included in the `chemicals` library.
Additionally a liquid mixture surface tension predictor objects
are implemented subclassing :obj:`MixtureProperty <thermo.utils.MixtureProperty>`.
For reporting bugs, adding feature requests, or submitting pull requests,
please use the `GitHub issue tracker <https://github.com/CalebBell/thermo/>`_.
.. contents:: :local:
Pure Liquid Surface Tension
===========================
.. autoclass:: SurfaceTension
:members: calculate, test_method_validity,
name, property_max, property_min,
units, ranked_methods
:undoc-members:
:show-inheritance:
:exclude-members:
.. autodata:: surface_tension_methods
Mixture Surface Tension
=======================
.. autoclass:: SurfaceTensionMixture
:members: calculate, test_method_validity,
name, property_max, property_min,
units, Tmin, Tmax, ranked_methods
:undoc-members:
:show-inheritance:
:exclude-members:
.. autodata:: surface_tension_mixture_methods
'''
__all__ = ['surface_tension_methods', 'SurfaceTension',
'surface_tension_mixture_methods', 'SurfaceTensionMixture']
from chemicals import interface, miscdata
from chemicals.dippr import EQ106
from chemicals.iapws import iapws95_Tc
from chemicals.interface import (
Aleem,
Brock_Bird,
Diguilio_Teja,
Jasper,
Miqueu,
Pitzer_sigma,
REFPROP_sigma,
Sastri_Rao,
Somayajulu,
Winterfeld_Scriven_Davis,
Zuo_Stenby,
sigma_IAPWS,
)
from chemicals.miscdata import lookup_VDI_tabular_data
from chemicals.utils import Vm_to_rho, mixing_simple, none_and_length_check, property_molar_to_mass
from fluids.numerics import isnan
from thermo.heat_capacity import HeatCapacityLiquid
from thermo.utils import IAPWS, LINEAR, REFPROP_FIT, VDI_TABULAR, MixtureProperty, TDependentProperty
from thermo.volume import VolumeLiquid
STREFPROP = 'REFPROP'
SOMAYAJULU2 = 'SOMAYAJULU2'
SOMAYAJULU = 'SOMAYAJULU'
JASPER = 'JASPER'
MIQUEU = 'MIQUEU'
BROCK_BIRD = 'BROCK_BIRD'
SASTRI_RAO = 'SASTRI_RAO'
PITZER = 'PITZER'
ZUO_STENBY = 'ZUO_STENBY'
HAKIM_STEINBERG_STIEL = 'HAKIM_STEINBERG_STIEL'
ALEEM = 'Aleem'
VDI_PPDS = 'VDI_PPDS'
surface_tension_methods = [IAPWS, REFPROP_FIT, STREFPROP, SOMAYAJULU2, SOMAYAJULU, VDI_PPDS, VDI_TABULAR,
JASPER, MIQUEU, BROCK_BIRD, SASTRI_RAO, PITZER,
ZUO_STENBY, ALEEM]
"""Holds all methods available for the :obj:`SurfaceTension` class, for use in
iterating over them."""
[docs]class SurfaceTension(TDependentProperty):
'''Class for dealing with surface tension as a function of temperature.
Consists of three coefficient-based methods and four data sources, one
source of tabular information, five corresponding-states estimators,
and one substance-specific method.
Parameters
----------
Tb : float, optional
Boiling point, [K]
MW : float, optional
Molecular weight, [g/mol]
Tc : float, optional
Critical temperature, [K]
Pc : float, optional
Critical pressure, [Pa]
Vc : float, optional
Critical volume, [m^3/mol]
Zc : float, optional
Critical compressibility
omega : float, optional
Acentric factor, [-]
StielPolar : float, optional
Stiel polar factor
Hvap_Tb : float
Mass enthalpy of vaporization at the normal boiling point [kg/m^3]
CASRN : str, optional
The CAS number of the chemical
Vml : float or callable, optional
Liquid molar volume at a given temperature and pressure or callable
for the same, [m^3/mol]
Cpl : float or callable, optional
Molar heat capacity of the fluid at a pressure and temperature or
or callable for the same, [J/mol/K]
load_data : bool, optional
If False, do not load property coefficients from data sources in files
[-]
extrapolation : str or None
None to not extrapolate; see
:obj:`TDependentProperty <thermo.utils.TDependentProperty>`
for a full list of all options, [-]
method : str or None, optional
If specified, use this method by default and do not use the ranked
sorting; an exception is raised if this is not a valid method for the
provided inputs, [-]
Notes
-----
To iterate over all methods, use the list stored in
:obj:`surface_tension_methods`.
**IAPWS**:
The IAPWS formulation for water,
:obj:`REFPROP_sigma <chemicals.interface.sigma_IAPWS>`
**STREFPROP**:
The REFPROP coefficient-based method, documented in the function
:obj:`REFPROP_sigma <chemicals.interface.REFPROP_sigma>` for 115 fluids from [5]_.
**SOMAYAJULU and SOMAYAJULU2**:
The Somayajulu coefficient-based method,
documented in the function :obj:`Somayajulu <chemicals.interface.Somayajulu>`. Both methods have data
for 64 fluids. The first data set if from [1]_, and the second
from [2]_. The later, revised coefficients should be used prefered.
**JASPER**:
Fit with a single temperature coefficient from Jaspen (1972)
as documented in the function :obj:`Jasper <chemicals.interface.Jasper>`. Data for 522 fluids is
available, as shown in [4]_ but originally in [3]_.
**BROCK_BIRD**:
CSP method documented in :obj:`Brock_Bird <chemicals.interface.Brock_Bird>`.
Most popular estimation method; from 1955.
**SASTRI_RAO**:
CSP method documented in :obj:`Sastri_Rao <chemicals.interface.Sastri_Rao>`.
Second most popular estimation method; from 1995.
**PITZER**:
CSP method documented in :obj:`Pitzer_sigma <chemicals.interface.Pitzer_sigma>`; from 1958.
**ZUO_STENBY**:
CSP method documented in :obj:`Zuo_Stenby <chemicals.interface.Zuo_Stenby>`; from 1997.
**MIQUEU**:
CSP method documented in :obj:`Miqueu <chemicals.interface.Miqueu>`.
**ALEEM**:
CSP method documented in :obj:`Aleem <chemicals.interface.Aleem>`.
**VDI_TABULAR**:
Tabular data in [6]_ along the saturation curve; interpolation is as
set by the user or the default.
**REFPROP_FIT**:
A series of higher-order polynomial fits to the calculated results from
the equations implemented in REFPROP.
See Also
--------
chemicals.interface.REFPROP_sigma
chemicals.interface.Somayajulu
chemicals.interface.Jasper
chemicals.interface.Brock_Bird
chemicals.interface.Sastri_Rao
chemicals.interface.Pitzer
chemicals.interface.Zuo_Stenby
chemicals.interface.Miqueu
chemicals.interface.Aleem
chemicals.interface.sigma_IAPWS
References
----------
.. [1] Somayajulu, G. R. "A Generalized Equation for Surface Tension from
the Triple Point to the Critical Point." International Journal of
Thermophysics 9, no. 4 (July 1988): 559-66. doi:10.1007/BF00503154.
.. [2] Mulero, A., M. I. Parra, and I. Cachadina. "The Somayajulu
Correlation for the Surface Tension Revisited." Fluid Phase
Equilibria 339 (February 15, 2013): 81-88.
doi:10.1016/j.fluid.2012.11.038.
.. [3] Jasper, Joseph J. "The Surface Tension of Pure Liquid Compounds."
Journal of Physical and Chemical Reference Data 1, no. 4
(October 1, 1972): 841-1010. doi:10.1063/1.3253106.
.. [4] Speight, James. Lange's Handbook of Chemistry. 16 edition.
McGraw-Hill Professional, 2005.
.. [5] Mulero, A., I. Cachadiña, and M. I. Parra. “Recommended
Correlations for the Surface Tension of Common Fluids.” Journal of
Physical and Chemical Reference Data 41, no. 4 (December 1, 2012):
043105. doi:10.1063/1.4768782.
.. [6] Gesellschaft, V. D. I., ed. VDI Heat Atlas. 2nd edition.
Berlin; New York:: Springer, 2010.
'''
name = 'Surface tension'
units = 'N/m'
interpolation_T = None
"""No interpolation transformation by default."""
interpolation_property = None
"""No interpolation transformation by default."""
interpolation_property_inv = None
"""No interpolation transformation by default."""
tabular_extrapolation_permitted = True
"""Allow tabular extrapolation by default; values below 0 will be obtained
at high temperatures."""
property_min = 0
"""Mimimum valid value of surface tension. This occurs at the critical
point exactly."""
property_max = 4.0
"""Maximum valid value of surface tension. Set to roughly twice that of
cobalt at its melting point."""
critical_zero = True
"""Whether or not the property is declining and reaching zero at the
critical point."""
ranked_methods = [IAPWS, REFPROP_FIT, STREFPROP, SOMAYAJULU2, SOMAYAJULU, VDI_PPDS, VDI_TABULAR,
JASPER, MIQUEU, BROCK_BIRD, SASTRI_RAO, PITZER,
ZUO_STENBY, ALEEM]
"""Default rankings of the available methods."""
_fit_force_n = {}
"""Dictionary containing method: fit_n, for use in methods which should
only ever be fit to a specific `n` value"""
_fit_force_n[JASPER] = 2
custom_args = ('MW', 'Tb', 'Tc', 'Pc', 'Vc', 'Zc', 'omega', 'StielPolar',
'Hvap_Tb', 'Vml', 'Cpl')
obj_references = pure_references = ('Vml', 'Cpl')
obj_references_types = pure_reference_types = (VolumeLiquid, HeatCapacityLiquid)
def __init__(self, MW=None, Tb=None, Tc=None, Pc=None, Vc=None, Zc=None,
omega=None, StielPolar=None, Hvap_Tb=None, CASRN='', Vml=None,
Cpl=None, extrapolation='DIPPR106_AB', **kwargs):
self.MW = MW
self.Tb = Tb
self.Tc = Tc
self.Pc = Pc
self.Vc = Vc
self.Zc = Zc
self.omega = omega
self.StielPolar = StielPolar
self.Hvap_Tb = Hvap_Tb
self.CASRN = CASRN
self.Vml = Vml
self.Cpl = Cpl
super().__init__(extrapolation, **kwargs)
@staticmethod
def _method_indexes():
'''Returns a dictionary of method: index for all methods
that use data files to retrieve constants. The use of this function
ensures the data files are not loaded until they are needed.
'''
return {STREFPROP: interface.sigma_data_Mulero_Cachadina.index,
SOMAYAJULU2: interface.sigma_data_Somayajulu2.index,
SOMAYAJULU: interface.sigma_data_Somayajulu.index,
VDI_TABULAR: list(miscdata.VDI_saturation_dict.keys()),
JASPER: interface.sigma_data_Jasper_Lange.index,
VDI_PPDS: interface.sigma_data_VDI_PPDS_11.index,
}
def load_all_methods(self, load_data):
r'''Method which picks out coefficients for the specified chemical
from the various dictionaries and DataFrames storing it. All data is
stored as attributes. This method also sets :obj:`Tmin`, :obj:`Tmax`,
and :obj:`all_methods` as a set of methods for which the data exists for.
Called on initialization only. See the source code for the variables at
which the coefficients are stored. The coefficients can safely be
altered once the class is initialized. This method can be called again
to reset the parameters.
'''
methods = []
self.all_methods = set()
self.T_limits = T_limits = {}
CASRN = self.CASRN
if load_data and CASRN:
if CASRN == '7732-18-5':
methods.append(IAPWS)
T_limits[IAPWS] = (273.15-25.0, iapws95_Tc)
if CASRN in interface.sigma_data_Mulero_Cachadina.index:
methods.append(STREFPROP)
sigma0, n0, sigma1, n1, sigma2, n2, Tc, self.STREFPROP_Tmin, self.STREFPROP_Tmax = interface.sigma_values_Mulero_Cachadina[interface.sigma_data_Mulero_Cachadina.index.get_loc(CASRN)].tolist()
self.STREFPROP_coeffs = [sigma0, n0, sigma1, n1, sigma2, n2, Tc]
T_limits[STREFPROP] = (self.STREFPROP_Tmin, self.STREFPROP_Tmax)
if CASRN in interface.sigma_data_Somayajulu2.index:
methods.append(SOMAYAJULU2)
self.SOMAYAJULU2_Tt, self.SOMAYAJULU2_Tc, A, B, C = interface.sigma_values_Somayajulu2[interface.sigma_data_Somayajulu2.index.get_loc(CASRN)].tolist()
self.SOMAYAJULU2_coeffs = [A, B, C]
T_limits[SOMAYAJULU2] = (self.SOMAYAJULU2_Tt, self.SOMAYAJULU2_Tc)
if CASRN in interface.sigma_data_Somayajulu.index:
methods.append(SOMAYAJULU)
self.SOMAYAJULU_Tt, self.SOMAYAJULU_Tc, A, B, C = interface.sigma_values_Somayajulu[interface.sigma_data_Somayajulu.index.get_loc(CASRN)].tolist()
self.SOMAYAJULU_coeffs = [A, B, C]
T_limits[SOMAYAJULU] = (self.SOMAYAJULU_Tt, self.SOMAYAJULU_Tc)
if CASRN in miscdata.VDI_saturation_dict:
Ts, props = lookup_VDI_tabular_data(CASRN, 'sigma')
# mercury missing values
if Ts:
self.add_tabular_data(Ts, props, VDI_TABULAR, check_properties=False)
del self._method
if CASRN in interface.sigma_data_Jasper_Lange.index:
methods.append(JASPER)
a, b, self.JASPER_Tmin, self.JASPER_Tmax = interface.sigma_values_Jasper_Lange[interface.sigma_data_Jasper_Lange.index.get_loc(CASRN)].tolist()
if isnan(self.JASPER_Tmax) or self.JASPER_Tmax == self.JASPER_Tmin:
# Some data is missing; and some is on a above the limit basis
self.JASPER_Tmax = a/b + 273.15
if isnan(self.JASPER_Tmin):
self.JASPER_Tmin = 0.0
self.JASPER_coeffs = [a, b]
T_limits[JASPER] = (self.JASPER_Tmin, self.JASPER_Tmax)
if CASRN in interface.sigma_data_VDI_PPDS_11.index:
Tm, Tc, A, B, C, D, E = interface.sigma_values_VDI_PPDS_11[interface.sigma_data_VDI_PPDS_11.index.get_loc(CASRN)].tolist()
self.VDI_PPDS_coeffs = [A, B, C, D, E]
self.VDI_PPDS_Tc = Tc
self.VDI_PPDS_Tm = Tm
methods.append(VDI_PPDS)
T_limits[VDI_PPDS] = (self.VDI_PPDS_Tm, self.VDI_PPDS_Tc)
if all((self.Tc, self.Vc, self.omega)):
methods.append(MIQUEU)
T_limits[MIQUEU] = (0.0, self.Tc)
if all((self.Tb, self.Tc, self.Pc)):
methods.append(BROCK_BIRD)
methods.append(SASTRI_RAO)
T_limits[BROCK_BIRD] = T_limits[SASTRI_RAO] = (0.0, self.Tc)
if all((self.Tc, self.Pc, self.omega)):
methods.append(PITZER)
methods.append(ZUO_STENBY)
T_limits[PITZER] = T_limits[ZUO_STENBY] = (1e-10, self.Tc)
if all((self.Tb, self.Hvap_Tb, self.MW)):
# Cache Cpl at Tb for ease of calculation of Tmax
self.Cpl_Tb = self.Cpl(self.Tb) if hasattr(self.Cpl, '__call__') else self.Cpl
if self.Cpl_Tb:
self.Cpl_Tb = property_molar_to_mass(self.Cpl_Tb, self.MW)
methods.append(ALEEM)
# Tmin and Tmax for this method is known
Tmax_possible = self.Tb + self.Hvap_Tb/self.Cpl_Tb
# This method will ruin solve_property as it is typically valid
# well above Tc. If Tc is available, limit it to that.
if self.Tc:
Tmax_possible = min(self.Tc, Tmax_possible)
T_limits[ALEEM] = (0.0, Tmax_possible)
self.all_methods.update(methods)
[docs] def calculate(self, T, method):
r'''Method to calculate surface tension of a liquid at temperature `T`
with a given method.
This method has no exception handling; see :obj:`T_dependent_property <thermo.utils.TDependentProperty.T_dependent_property>`
for that.
Parameters
----------
T : float
Temperature at which to calculate surface tension, [K]
method : str
Name of the method to use
Returns
-------
sigma : float
Surface tension of the liquid at T, [N/m]
'''
if method == STREFPROP:
sigma0, n0, sigma1, n1, sigma2, n2, Tc = self.STREFPROP_coeffs
sigma = REFPROP_sigma(T, Tc=Tc, sigma0=sigma0, n0=n0, sigma1=sigma1, n1=n1,
sigma2=sigma2, n2=n2)
elif method == VDI_PPDS:
sigma = EQ106(T, self.VDI_PPDS_Tc, *self.VDI_PPDS_coeffs)
elif method == SOMAYAJULU2:
A, B, C = self.SOMAYAJULU2_coeffs
sigma = Somayajulu(T, Tc=self.SOMAYAJULU2_Tc, A=A, B=B, C=C)
elif method == SOMAYAJULU:
A, B, C = self.SOMAYAJULU_coeffs
sigma = Somayajulu(T, Tc=self.SOMAYAJULU_Tc, A=A, B=B, C=C)
elif method == JASPER:
sigma = Jasper(T, a=self.JASPER_coeffs[0], b=self.JASPER_coeffs[1])
elif method == IAPWS:
sigma = sigma_IAPWS(T)
elif method == BROCK_BIRD:
sigma = Brock_Bird(T, self.Tb, self.Tc, self.Pc)
elif method == SASTRI_RAO:
sigma = Sastri_Rao(T, self.Tb, self.Tc, self.Pc)
elif method == PITZER:
sigma = Pitzer_sigma(T, self.Tc, self.Pc, self.omega)
elif method == ZUO_STENBY:
sigma = Zuo_Stenby(T, self.Tc, self.Pc, self.omega)
elif method == MIQUEU:
sigma = Miqueu(T, self.Tc, self.Vc, self.omega)
elif method == ALEEM:
Cpl = self.Cpl(T) if hasattr(self.Cpl, '__call__') else self.Cpl
Cpl = property_molar_to_mass(Cpl, self.MW)
try:
Vml = self.Vml.T_dependent_property(T)
except:
try:
Vml = self.Vml(T)
except:
Vml = self.Vml
rhol = Vm_to_rho(Vml, self.MW)
sigma = Aleem(T=T, MW=self.MW, Tb=self.Tb, rhol=rhol, Hvap_Tb=self.Hvap_Tb, Cpl=Cpl)
else:
return self._base_calculate(T, method)
return sigma
[docs] def test_method_validity(self, T, method):
r'''Method to check the validity of a method. Follows the given
ranges for all coefficient-based methods. For CSP methods, the models
are considered valid from 0 K to the critical point. For tabular data,
extrapolation outside of the range is used if
:obj:`tabular_extrapolation_permitted` is set; if it is, the extrapolation
is considered valid for all temperatures.
It is not guaranteed that a method will work or give an accurate
prediction simply because this method considers the method valid.
Parameters
----------
T : float
Temperature at which to test the method, [K]
method : str
Name of the method to test
Returns
-------
validity : bool
Whether or not a method is valid
'''
validity = True
if method == STREFPROP:
if T < self.STREFPROP_Tmin or T > self.STREFPROP_Tmax:
validity = False
elif method == VDI_PPDS:
if T > self.VDI_PPDS_Tc:
# Could also check for low temp, but not necessary as it extrapolates
validity = False
elif method == SOMAYAJULU2:
if T < self.SOMAYAJULU2_Tt or T > self.SOMAYAJULU2_Tc:
validity = False
elif method == SOMAYAJULU:
if T < self.SOMAYAJULU_Tt or T > self.SOMAYAJULU_Tc:
validity = False
elif method == JASPER:
if T < self.JASPER_Tmin or T > self.JASPER_Tmax:
validity = False
elif method in [BROCK_BIRD, SASTRI_RAO, PITZER, ZUO_STENBY, MIQUEU]:
if T > self.Tc:
validity = False
elif method == ALEEM:
if T > self.Tb + self.Hvap_Tb/self.Cpl_Tb:
validity = False
else:
return super().test_method_validity(T, method)
return validity
WINTERFELDSCRIVENDAVIS = 'Winterfeld, Scriven, and Davis (1978)'
DIGUILIOTEJA = 'Diguilio and Teja (1988)'
surface_tension_mixture_methods = [WINTERFELDSCRIVENDAVIS, DIGUILIOTEJA, LINEAR]
"""Holds all methods available for the :obj:`SurfaceTensionMixture` class, for use in
iterating over them."""
[docs]class SurfaceTensionMixture(MixtureProperty):
'''Class for dealing with surface tension of a mixture as a function of
temperature, pressure, and composition.
Consists of two mixing rules specific to surface tension, and mole
weighted averaging.
Prefered method is :obj:`Winterfeld_Scriven_Davis <chemicals.interface.Winterfeld_Scriven_Davis>` which requires mole
fractions, pure component surface tensions, and the molar density of each
pure component. :obj:`Diguilio_Teja <chemicals.interface.Diguilio_Teja>` is of similar accuracy, but requires
the surface tensions of pure components at their boiling points, as well
as boiling points and critical points and mole fractions. An ideal mixing
rule based on mole fractions, **LINEAR**, is also available and is still
relatively accurate.
Parameters
----------
MWs : list[float], optional
Molecular weights of all species in the mixture, [g/mol]
Tbs : list[float], optional
Boiling points of all species in the mixture, [K]
Tcs : list[float], optional
Critical temperatures of all species in the mixture, [K]
CASs : list[str], optional
The CAS numbers of all species in the mixture, [-]
SurfaceTensions : list[SurfaceTension], optional
SurfaceTension objects created for all species in the mixture [-]
VolumeLiquids : list[VolumeLiquid], optional
VolumeLiquid objects created for all species in the mixture [-]
correct_pressure_pure : bool, optional
Whether to try to use the better pressure-corrected pure component
models or to use only the T-only dependent pure species models, [-]
Notes
-----
To iterate over all methods, use the list stored in
:obj:`surface_tension_mixture_methods`.
**WINTERFELDSCRIVENDAVIS**:
Mixing rule described in :obj:`Winterfeld_Scriven_Davis <chemicals.interface.Winterfeld_Scriven_Davis>`.
**DIGUILIOTEJA**:
Mixing rule described in :obj:`Diguilio_Teja <chemicals.interface.Diguilio_Teja>`.
**LINEAR**:
Mixing rule described in :obj:`mixing_simple <chemicals.utils.mixing_simple>`.
See Also
--------
chemicals.interface.Winterfeld_Scriven_Davis
chemicals.interface.Diguilio_Teja
References
----------
.. [1] Poling, Bruce E. The Properties of Gases and Liquids. 5th edition.
New York: McGraw-Hill Professional, 2000.
'''
name = 'Surface tension'
units = 'N/m'
property_min = 0
"""Mimimum valid value of surface tension. This occurs at the critical
point exactly."""
property_max = 4.0
"""Maximum valid value of surface tension. Set to roughly twice that of
cobalt at its melting point."""
ranked_methods = [WINTERFELDSCRIVENDAVIS, DIGUILIOTEJA, LINEAR]
pure_references = ('SurfaceTensions', 'VolumeLiquids')
pure_reference_types = (SurfaceTension, VolumeLiquid)
pure_constants = ('MWs', 'Tbs', 'Tcs')
custom_args = pure_constants
def __init__(self, MWs=[], Tbs=[], Tcs=[], CASs=[], SurfaceTensions=[],
VolumeLiquids=[], correct_pressure_pure=False, **kwargs):
self.MWs = MWs
self.Tbs = Tbs
self.Tcs = Tcs
self.CASs = CASs
self.SurfaceTensions = SurfaceTensions
self.VolumeLiquids = VolumeLiquids
super().__init__(correct_pressure_pure=correct_pressure_pure, **kwargs)
def load_all_methods(self):
r'''Method to initialize the object by precomputing any values which
may be used repeatedly and by retrieving mixture-specific variables.
All data are stored as attributes. This method also sets :obj:`Tmin`,
:obj:`Tmax`, and :obj:`all_methods` as a set of methods which should
work to calculate the property.
Called on initialization only. See the source code for the variables at
which the coefficients are stored. The coefficients can safely be
altered once the class is initialized. This method can be called again
to reset the parameters.
'''
methods = set()
methods.add(LINEAR) # Needs sigma
methods.add(WINTERFELDSCRIVENDAVIS) # Nothing to load, needs rhoms, sigma
if none_and_length_check([self.Tbs, self.Tcs]):
self.sigmas_Tb = [i(Tb) for i, Tb in zip(self.SurfaceTensions, self.Tbs)]
if none_and_length_check([self.sigmas_Tb]):
methods.add(DIGUILIOTEJA)
self.all_methods = methods
[docs] def calculate(self, T, P, zs, ws, method):
r'''Method to calculate surface tension of a liquid mixture at
temperature `T`, pressure `P`, mole fractions `zs` and weight fractions
`ws` with a given method.
This method has no exception handling; see :obj:`mixture_property <thermo.utils.MixtureProperty.mixture_property>`
for that.
Parameters
----------
T : float
Temperature at which to calculate the property, [K]
P : float
Pressure at which to calculate the property, [Pa]
zs : list[float]
Mole fractions of all species in the mixture, [-]
ws : list[float]
Weight fractions of all species in the mixture, [-]
method : str
Name of the method to use
Returns
-------
sigma : float
Surface tension of the liquid at given conditions, [N/m]
'''
if method == DIGUILIOTEJA:
return Diguilio_Teja(T=T, xs=zs, sigmas_Tb=self.sigmas_Tb,
Tbs=self.Tbs, Tcs=self.Tcs)
elif method == WINTERFELDSCRIVENDAVIS:
sigmas = self.calculate_pures(T)
Vms = self.calculate_pures_corrected(T, P, fallback=False, objs=self.VolumeLiquids)
rhoms = [1.0/v for v in Vms]
return Winterfeld_Scriven_Davis(zs, sigmas, rhoms)
return super().calculate(T, P, zs, ws, method)
[docs] def test_method_validity(self, T, P, zs, ws, method):
# LINEAR and WINTERFELDSCRIVENDAVIS need to calculate sigma for pure
# species - doesn't work above Tc for any compound.
# DIGUILIOTEJA needs Tcs, not sure.
if method in [LINEAR, DIGUILIOTEJA, WINTERFELDSCRIVENDAVIS]:
return True
return super().test_method_validity(T, P, zs, ws, method)