Methods in the cpa class
ThermoPack - Latest (beta)
The cpa class, found in addon/pycThermopack/thermopack/cpa.py, inherits from the cubic class, and is the interface to the
Cubic Plus Association Equation of State. This class implements utility methods to access mixing parameters etc.
Table of contents
Constructor
Methods to initialise Cubic Plus Association model.
Table of contents
__init__(self, comps=None, eos='SRK', mixing='vdW', alpha='Classic', parameter_reference='Default')
Initialize cubic plus association model in thermopack
If no components are specified, model must be initialized for specific components later by direct call to ‘init’
Model can at any time be re-initialized for new components or parameters by direct calls to ‘init’
Args:
comps (str, optional):
Comma separated list of component names
eos (str, optional):
Cubic equation of state. Defaults to “SRK”.
mixing (str, optional):
Mixture model. Defaults to “vdW”.
alpha (str, optional):
Alpha model. Defaults to “Classic”.
parameter_reference (str, optional):
Which parameters to use?. Defaults to “Default”.
init(self, comps, eos='SRK', mixing='vdW', alpha='Classic', parameter_reference='Default')
Initialize cubic plus association model in thermopack
Args:
comps (str):
Comma separated list of component names
eos (str, optional):
Cubic equation of state. Defaults to “SRK”.
mixing (str, optional):
Mixture model. Defaults to “vdW”.
alpha (str, optional):
Alpha model. Defaults to “Classic”.
parameter_reference (str, optional):
Which parameters to use?. Defaults to “Default”.
Utility methods
Set- and get methods for interaction parameters, mixing parameters …
Table of contents
get_kij(self, c1, c2)
Get attractive energy interaction parameter
Args:
c1 (int):
Component one
c2 (int):
Component two
Returns:
kij (array_like):
i-j interaction parameter (2 parameters)
get_pure_params(self, ic)
Get pure parameters
Args:
ic (int):
Component index
Returns:
params (array_like):
a0 (Pa*L^2/mol^2), b (L/mol), eps (J/mol), beta (-), c1 (-)
print_cpa_report(self)
Print cpa parameters
Parameters printed are the five pure parameters
a0, b, epsilon, beta, c1, and the binary parameter
for the cubic part, kij_a, and for the association part, kij_eps.
set_cpa_formulation(self, simplified, elliot)
Set CPA formulation Args: simplified (bool): Use simplified form for rdf in CPA? elliot (bool): use Elliot mixing rule for association Deltas?
set_kij(self, c1, c2, kij_a, kij_eps)
Set attractive energy interaction parameter
Args:
c1 (int):
Component one
c2 (int):
Component two
kij_a (int):
cubic i-j interaction parameter
kij_eps (int):
association i-j interaction parameter
set_pure_params(self, ic, params)
Set pure parameters Input a0, b in their conventional (non-SI) units, beta and eps in SI units, c1 dimensionless.
Args:
ic (int):
Component index
params (array_like):
a0 (Pa*L^2/mol^2), b (L/mol), eps (J/mol), beta (-), c1 (-)
use_simplified_cpa(self, simplified)
Use simplified form for rdf in CPA
Args:
simplified (bool):
True if simplified