Chemical equilibrium at constant entropy and volume#
1% -------------------------------------------------------------------------
2% EXAMPLE: SV
3% Compute Isentropic compression/expansion and equilibrium composition at
4% a defined set of specific volume (vSpecific = 0.5:2 m3/kg) for a lean
5% CH4-air mixture at defined specific entropy, and an equivalence ratio
6% phi 0.5 [-]
7%
8% See wiki or setListspecies method from ChemicalSystem class for predefined
9% sets of species
10%
11% @author: Alberto Cuadra Lara
12%
13% Last update October 16 2025
14% -------------------------------------------------------------------------
15
16% Import packages
17import combustiontoolbox.databases.NasaDatabase
18import combustiontoolbox.core.*
19import combustiontoolbox.equilibrium.*
20
21% Get Nasa database
22DB = NasaDatabase();
23
24% Define chemical system
25system = ChemicalSystem(DB);
26
27% Initialize mixture
28mix = Mixture(system);
29
30% Define chemical state
31set(mix, {'CH4'}, 'fuel', 1);
32set(mix, {'N2', 'O2', 'Ar', 'CO2'}, 'oxidizer', [78.084, 20.9476, 0.9365, 0.0319] / 20.9476);
33
34% Define properties
35mixArray = setProperties(mix, 'entropySpecific', mix.sSpecific, 'volume', 0.5:0.01:2, 'equivalenceRatio', 0.5);
36
37% Initialize solver
38solver = EquilibriumSolver('problemType', 'SV');
39
40% Solve problem
41solver.solveArray(mixArray);
42
43% Generate report
44report(solver, mixArray);