cantera/interfaces/python/Cantera/stoich.py
Ray Speth 2528df0f75 Reorganized source tree structure
These changes make it unnecessary to copy header files around during
the build process, which tends to confuse IDEs and debuggers. The
headers which comprise Cantera's external C++ interface are now in
the 'include' directory.

All of the samples and demos are now in the 'samples' subdirectory.
2012-02-12 02:27:14 +00:00

46 lines
1.4 KiB
Python
Executable file

from Cantera import exceptions
from Cantera.num import array
from Cantera.elements import elementMoles
def det3(A):
"""Determinant of a 3x3 matrix."""
return (A[0,0]*(A[1,1]*A[2,2] - A[1,2]*A[2,1])
- A[0,1]*(A[1,0]*A[2,2] - A[1,2]*A[2,0])
+ A[0,2]*(A[1,0]*A[2,1] - A[2,0]*A[1,1]))
def stoich_fuel_to_oxidizer(mix, fuel, oxidizer):
"""Fuel to oxidizer ratio for stoichiometric combustion.
This function only works for fuels composed of carbon, hydrogen,
and/or oxygen. The fuel to oxidizer ratio is returned that results in
"""
# fuel
mix.setMoleFractions(fuel)
f_carbon = elementMoles(mix, 'C')
f_oxygen = elementMoles(mix, 'O')
f_hydrogen = elementMoles(mix, 'H')
#oxidizer
mix.setMoleFractions(oxidizer)
o_carbon = elementMoles(mix, 'C')
o_oxygen = elementMoles(mix, 'O')
o_hydrogen = elementMoles(mix, 'H')
B = array([f_carbon, f_hydrogen, f_oxygen],'d')
A = array([[1.0, 0.0, -o_carbon],
[0.0, 2.0, -o_hydrogen],
[2.0, 1.0, -o_oxygen]], 'd')
num = array(A,'d')
num[:,2] = B
r = det3(num)/det3(A)
if r <= 0.0:
raise CanteraError('negative or zero computed stoichiometric fuel/oxidizer ratio!')
return 1.0/r
if __name__ == "__main__":
g = GRI30()
print stoich_fuel_to_oxidizer(g, 'CH4:1', 'O2:1')