"""Module containing element dict, species and reaction classes, and constants.
"""
# Python 2 compatibility
from __future__ import division
# Standard libraries
import math
import numpy as np
__all__ = ['RU', 'RUC', 'RU_JOUL', 'PA', 'get_elem_wt',
'ReacInfo', 'SpecInfo', 'calc_spec_smh']
# universal gas constants, SI units
RU = 8314.4621 # J/(kmole * K)
RU_JOUL = 8.3144621
RUC = (RU / 4.18400) # cal/(mole * K)
# Avogadro's number
AVAG = 6.0221367e23
# pressure of one standard atmosphere [Pa]
PA = 101325.0
class CommonEqualityMixin(object):
"""Base class for `ReacInfo` and `SpecInfo` classes for equality comparison
"""
def __eq__(self, other):
try:
for key, value in self.__dict__.items():
if not key in other.__dict__:
return False
if isinstance(value, np.ndarray):
if not np.array_equal(value, other.__dict__[key]):
return False
elif isinstance(value, list):
if not all([any(x == y for y in other.__dict__[key]) for x in value]):
return False
elif value != other.__dict__[key]:
return False
return True
except Exception as e:
return False
def __ne__(self, other):
return not self.__eq__(other)
[docs]def get_elem_wt():
"""Returns dict with built-in element names and atomic weights [kg/kmol].
Attributes
----------
None
Returns
-------
elem_wt : dict
Dictionary with element name keys and atomic weight [kg/kmol] values.
"""
elem_wt = dict([
('h', 1.00794), ('he', 4.00260), ('li', 6.93900),
('be', 9.01220), ('b', 10.81100), ('c', 12.0110),
('n', 14.00674), ('o', 15.99940), ('f', 18.99840),
('ne', 20.18300), ('na', 22.98980), ('mg', 24.31200),
('al', 26.98150), ('si', 28.08600), ('p', 30.97380),
('s', 32.06400), ('cl', 35.45300), ('ar', 39.94800),
('k', 39.10200), ('ca', 40.08000), ('sc', 44.95600),
('ti', 47.90000), ('v', 50.94200), ('cr', 51.99600),
('mn', 54.93800), ('fe', 55.84700), ('co', 58.93320),
('ni', 58.71000), ('cu', 63.54000), ('zn', 65.37000),
('ga', 69.72000), ('ge', 72.59000), ('as', 74.92160),
('se', 78.96000), ('br', 79.90090), ('kr', 83.80000),
('rb', 85.47000), ('sr', 87.62000), ('y', 88.90500),
('zr', 91.22000), ('nb', 92.90600), ('mo', 95.94000),
('tc', 99.00000), ('ru', 101.07000), ('rh', 102.90500),
('pd', 106.40000), ('ag', 107.87000), ('cd', 112.40000),
('in', 114.82000), ('sn', 118.69000), ('sb', 121.75000),
('te', 127.60000), ('i', 126.90440), ('xe', 131.30000),
('cs', 132.90500), ('ba', 137.34000), ('la', 138.91000),
('ce', 140.12000), ('pr', 140.90700), ('nd', 144.24000),
('pm', 145.00000), ('sm', 150.35000), ('eu', 151.96000),
('gd', 157.25000), ('tb', 158.92400), ('dy', 162.50000),
('ho', 164.93000), ('er', 167.26000), ('tm', 168.93400),
('yb', 173.04000), ('lu', 174.99700), ('hf', 178.49000),
('ta', 180.94800), ('w', 183.85000), ('re', 186.20000),
('os', 190.20000), ('ir', 192.20000), ('pt', 195.09000),
('au', 196.96700), ('hg', 200.59000), ('tl', 204.37000),
('pb', 207.19000), ('bi', 208.98000), ('po', 210.00000),
('at', 210.00000), ('rn', 222.00000), ('fr', 223.00000),
('ra', 226.00000), ('ac', 227.00000), ('th', 232.03800),
('pa', 231.00000), ('u', 238.03000), ('np', 237.00000),
('pu', 242.00000), ('am', 243.00000), ('cm', 247.00000),
('bk', 249.00000), ('cf', 251.00000), ('es', 254.00000),
('fm', 253.00000), ('d', 2.01410), ('e', 5.48578e-4)
])
return elem_wt
[docs]class ReacInfo(CommonEqualityMixin):
"""Reaction class.
Contains all information about a single reaction.
Attributes
----------
rev : bool
True if reversible reaction, False if irreversible.
reactants : list of str
List of reactant species names.
reac_nu : list of int/float
List of reactant stoichiometric coefficients, either int or float.
products : list of str
List of product species names.
prod_nu : list of int/float
List of product stoichiometric coefficients, either int or float.
A : float
Arrhenius pre-exponential coefficient.
b : float
Arrhenius temperature exponent.
E : float
Arrhenius activation energy.
rev_par : list of float, optional
List of reverse Arrhenius coefficients (default empty).
dup : bool, optional
Duplicate reaction flag (default False).
thd : bool, optional
Third-body reaction flag (default False).
thd_body : list of list of [str, float], optional
List of third body names and efficiencies (default empty).
pdep : bool, optional
Pressure-dependence flag (default False).
pdep_sp : str, optional
Name of specific third-body or 'M' (default '').
low : list of float, optional
List of low-pressure-limit Arrhenius coefficients (default empty).
high : list of float, optional
List of high-pressure-limit Arrhenius coefficients (default empty).
troe : bool, optional
Troe pressure-dependence formulation flag (default False).
troe_par : list of float, optional
List of Troe formulation constants (default empty).
sri : bool, optional
SRI pressure-dependence formulation flag (default False).
sri_par : list of float, optional
List of SRI formulation constants (default empty).
Notes
-----
`rev` does not require `rev_par`; if no explicit coefficients, the
reverse reaction rate will be calculated through the equilibrium
constant.
Only one of [`low`,`high`] can be defined.
If `troe` and `sri` are both False, then the Lindemann is assumed.
"""
def __init__(self, rev, reactants, reac_nu, products, prod_nu, A, b, E):
self.reac = reactants
self.reac_nu = reac_nu
self.prod = products
self.prod_nu = prod_nu
## Arrhenius coefficients
# pre-exponential factor [m, kmol, s]
self.A = A
# Temperature exponent [-]
self.b = b
# Activation energy, stored as activation temperature [K]
self.E = E
# reversible reaction properties
self.rev = rev
self.rev_par = [] # reverse A, b, E
# duplicate reaction
self.dup = False
# third-body efficiencies
self.thd_body = False
self.thd_body_eff = [] # in pairs with species and efficiency
# pressure dependence
self.pdep = False
self.pdep_sp = ''
self.low = []
self.high = []
self.troe = False
self.troe_par = []
self.sri = False
self.sri_par = []
# Parameters for pressure-dependent reaction parameterized by
# bivariate Chebyshev polynomial in temperature and pressure.
self.cheb = False
# Number of temperature values over which fit computed.
self.cheb_n_temp = 0
# Number of pressure values over which fit computed.
self.cheb_n_pres = 0
# Pressure limits for Chebyshev fit [Pa]
self.cheb_plim = [0.001 * PA, 100. * PA]
# Temperature limits for Chebyshev fit [K]
self.cheb_tlim = [300., 2500.]
# 2D array of Chebyshev fit coefficients
self.cheb_par = None
# Parameters for pressure-dependent reaction parameterized by
# logarithmically interpolating between Arrhenius rate expressions at
# various pressures.
self.plog = False
# List of arrays with [pressure [Pa], A, b, E]
self.plog_par = None
[docs]class SpecInfo(CommonEqualityMixin):
"""Species class.
Contains all information about a single species.
Attributes
----------
name : str
Name of species.
elem : list of list of [str, float]
Elemental composition in [element, number] pairs.
mw : float
Molecular weight.
hi : list of float
High-temperature range NASA thermodynamic coefficients.
lo : list of float
Low-temperature range NASA thermodynamic coefficients.
Trange : list of float
Temperatures defining ranges of thermodynamic polynomial fits
(low, middle, high), default ([300, 1000, 5000]).
"""
def __init__(self, name):
self.name = name
# elemental composition
self.elem = []
# molecular weight [kg/kmol]
self.mw = 0.0
# high-temp range thermodynamic coefficients
self.hi = np.zeros(7)
# low-temp range thermodynamic coefficients
self.lo = np.zeros(7)
# temperature [K] range for thermodynamic coefficients
self.Trange = [300.0, 1000.0, 5000.0]
[docs]def calc_spec_smh(T, specs):
"""Calculate standard-state entropies minus enthalpies for all species.
Parameters
----------
T : float
Temperature of gas mixture.
specs : list of SpecInfo
List of species.
Returns
-------
spec_smh : list of float
List of species' standard-state entropies minus enthalpies.
"""
spec_smh = []
Tlog = math.log(T)
T2 = T * T
T3 = T2 * T
T4 = T3 * T
Thalf = T / 2.0
T2 = T2 / 6.0
T3 = T3 / 12.0
T4 = T4 / 20.0
for sp in specs:
if T <= sp.Trange[1]:
smh = (sp.lo[0] * (Tlog - 1.0) + sp.lo[1] * Thalf + sp.lo[2] *
T2 + sp.lo[3] * T3 + sp.lo[4] * T4 - (sp.lo[5] / T) +
sp.lo[6]
)
else:
smh = (sp.hi[0] * (Tlog - 1.0) + sp.hi[1] * Thalf + sp.hi[2] *
T2 + sp.hi[3] * T3 + sp.hi[4] * T4 - (sp.hi[5] / T) +
sp.hi[6]
)
spec_smh.append(smh)
return (spec_smh)
