Methods in the saftvrmie class
ThermoPack - 2.2
The saftvrmie class, found in addon/pycThermopack/thermopack/saftvrmie.py, is the interface to the
SAFT-VR Mie Equation of State. This class inherits the saft class, which in turn inherits the
thermo class. This class implements methods for modifying fluid parameters and which terms
are included in the model.
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Constructor
Methods to initialise SAFT-VR Mie model.
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__init__(self, comps=None, parameter_reference='Default')
Initialize SAFT-VR Mie 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
parameter_reference (str, optional):
Which parameters to use?. Defaults to “Default”.
init(self, comps, parameter_reference='Default')
Initialize SAFT-VR Mie model in thermopack
Args:
comps (str):
Comma separated list of component names
parameter_reference (str, optional):
Which parameters to use?. Defaults to “Default”.
Utility methods
Set- and get methods for interaction parameters and pure fluid parameters.
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a1(self, temp, volume, n)
Get a1 term
Args:
temp (float):
Temperature (K)
volume (float):
Volume (m3)
n (array like):
Mol numbers (mol)
Returns:
a1 (float):
First order perturbation (K/mol)
a2(self, temp, volume, n)
Get a2 term
Args:
temp (float):
Temperature (K)
volume (float):
Volume (m3)
n (array like):
Mol numbers (mol)
Returns:
a2 (float):
Second order perturbation (K^2/mol)
a3(self, temp, volume, n)
Get a3 term
Args:
temp (float):
Temperature (K)
volume (float):
Volume (m3)
n (array like):
Mol numbers (mol)
Returns:
a3 (float):
Second order perturbation (K^3/mol)
a_hs(self, temp, volume, n)
Get hardsphere term
Args:
temp (float):
Temperature (K)
volume (float):
Volume (m3)
n (array like):
Mol numbers (mol)
Returns:
a_hs (float):
Second order perturbation (1/mol)
get_eps_kij(self, c1, c2)
Get binary well depth interaction parameter
Args:
c1 (int):
Component one
c2 (int):
Component two
Returns:
kij (float):
Well depth interaction parameter
get_lr_gammaij(self, c1, c2)
Get the interaction parameter gammaij for the lambda_r combining rule
Args:
c1 (int):
Component one
c2 (int):
Component two
Returns:
gammaij (float):
Repulsive exponent interaction parameter
get_pure_fluid_param(self, ic)
Set pure fluid parameters
Args:
ic (int):
Component index
Returns;
m (float):
Mean number of segments.
sigma (float):
Temperature-independent segment diameter [m].
eps_div_k (float):
Well depth divided by Boltzmann’s const. [K].
lambda_a (float):
Attractive exponent of the Mie potential
lambda_r (float):
Repulsive exponent of the Mie potential
get_sigma_lij(self, c1, c2)
Get the interaction parameter lij for the sigma combining rule (controlling non-additivity)
Args:
c1 (int):
Component one
c2 (int):
Component two
Returns:
lij (float):
Sigma interaction parameter
print_saft_parameters(self, c)
Print saft parameters for component c
Args:
c (int):
Component index (FORTRAN)
set_eps_kij(self, c1, c2, kij)
Set binary well depth interaction parameter
Args:
c1 (int):
Component one
c2 (int):
Component two
kij (float):
Well depth interaction parameter
set_lr_gammaij(self, c1, c2, gammaij)
Set the interaction parameter gammaij for the lambda_r combining rule
Args:
c1 (int):
Component one
c2 (int):
Component two
gammaij (float):
Repulsive exponent interaction parameter
set_pure_fluid_param(self, ic, m, sigma, eps_div_kb, lambda_a, lambda_r)
Set pure fluid parameters
Args:
ic (int):
Component index
m (float):
Mean number of segments.
sigma (float):
Temperature-independent segment diameter [m].
eps_div_kb (float):
Well depth divided by Boltzmann’s const. [K].
lambda_a (float):
Attractive exponent of the Mie potential
lambda_r (float):
Repulsive exponent of the Mie potential
set_sigma_lij(self, c1, c2, lij)
Set the interaction parameter lij for the sigma combining rule (controlling non-additivity)
Args:
c1 (int):
Component one
c2 (int):
Component two
lij (float):
Sigma interaction parameter
Model control
Control which contributions to the residual Helmholtz energy are included, and the hard-sphere reference term.
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model_control_a1(self, active)
Enable/disable first dispersion term.
Args:
active (bool):
Enable/disable first dispersion term
model_control_a2(self, active)
Enable/disable second dispersion term.
Args:
active (bool):
Enable/disable second dispersion term
model_control_a3(self, active)
Enable/disable third dispersion term.
Args:
active (bool):
Enable/disable third dispersion term
model_control_chain(self, active)
Enable/disable chain term.
Args:
active (bool):
Enable/disable chain term
model_control_hard_sphere(self, active)
Enable/disable hard-sphere term.
Args:
active (bool):
Enable/disable hard-sphere dispersion term
set_hard_sphere_reference(self, reference, exact_binary_dhs=None, enable_hs_extra=None)
Set hard-sphere reference.
Args:
reference (str):
“LAFITTE”, “ADDITIVE”, “NON-ADDITIVE”
exact_binary_dhs (bool):
Calculate d_ij from sigma_ij and epsilon_ij
or simply as d_ij = (d_ii + d_jj)/2
enable_hs_extra (bool):
Correction of A_HS due to non-additive d_ij
Model performance
Methods to tune computation efficiency etc.
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enable_temperature_cache(self, enable=True)
Enable/disable temperature cache.
Args:
enable (bool):
Enable/disable temperature cache