Warning

This documentation is for an old version of Cantera. You can find docs for newer versions here.

flame2.m

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  An axisymmetric stagnation-point non-premixed flame
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

t0 = cputime;  % record the starting time

% parameter values
p          =   oneatm;              % pressure
tin        =   300.0;               % inlet temperature
mdot_o     =   0.72;                % air, kg/m^2/s
mdot_f     =   0.24;                % fuel, kg/m^2/s

rxnmech    =  'gri30.xml';          % reaction mechanism file
transport  =  'Mix';                % transport model
comp1       =  'O2:0.21, N2:0.78, AR:0.01';  % air composition
comp2       =  'C2H6:1';            % fuel composition

initial_grid = 0.02*[0.0 0.2 0.4 0.6 0.8 1.0];  % m

tol_ss    = [1.0e-5 1.0e-13];       % [rtol atol] for steady-state
                                    % problem
tol_ts    = [1.0e-4 1.0e-13];        % [rtol atol] for time stepping

loglevel  = 1;                      % amount of diagnostic output (0
                                    % to 5)

refine_grid = 1;                    % 1 to enable refinement, 0 to
                                    % disable

%%%%%%%%%%%%%%%% create the gas object %%%%%%%%%%%%%%%%%%%%%%%%
%
% This object will be used to evaluate all thermodynamic, kinetic,
% and transport properties
%
gas = GRI30('Mix'); %IdealGasMix(rxnmech, transport);

% set its state to that of the  fuel (arbitrary)
set(gas,'T', tin, 'P', p, 'X', comp2);

%%%%%%%%%%%%%%%% create the flow object %%%%%%%%%%%%%%%%%%%%%%%

f = AxisymmetricFlow(gas,'flow');

set(f, 'P', p, 'grid', initial_grid);
set(f, 'tol', tol_ss, 'tol-time', tol_ts);

%%%%%%%%%%%%%%% create the air inlet %%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  The temperature, mass flux, and composition (relative molar) may be
%  specified.
%
inlet_o = Inlet('air_inlet');
set(inlet_o, 'T', tin, 'MassFlux', mdot_o, 'X', comp1);

%%%%%%%%%%%%%% create the fuel inlet %%%%%%%%%%%%%%%%%%%%%%%%%%%%
inlet_f = Inlet('fuel_inlet');
set(inlet_f, 'T', tin, 'MassFlux', mdot_f, 'X', comp2);

%%%%%%%%%%%%% create the flame object  %%%%%%%%%%%%
%
% Once the component parts have been created, they can be assembled
% to create the flame object.
%
fl = flame(gas, inlet_o, f, inlet_f);

% if the starting solution is to be read from a previously-saved
% solution, uncomment this line and edit the file name and solution id.
%restore(fl,'h2flame2.xml', 'energy')

% solve with fixed temperature profile first
solve(fl, loglevel, refine_grid);

%%%%%%%%%%%% enable the energy equation %%%%%%%%%%%%%%%%%%%%%
%
%  The energy equation will now be solved to compute the
%  temperature profile. We also tighten the grid refinement
%  criteria to get an accurate final solution.
%

enableEnergy(f);
setRefineCriteria(fl, 2, 200.0, 0.1, 0.1);
solve(fl, loglevel, refine_grid);
saveSoln(fl,'c2h6.xml','energy',['solution with energy equation']);

%%%%%%%%%% show statistics %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
writeStats(fl);
elapsed = cputime - t0;
e = sprintf('Elapsed CPU time: %10.4g',elapsed);
disp(e);

%%%%%%%%%% make plots %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

figure(1);
subplot(2,3,1);
plotSolution(fl, 'flow', 'T');
title('Temperature [K]');
subplot(2,3,2);
plotSolution(fl, 'flow', 'C2H6');
title('C2H6 Mass Fraction');
subplot(2,3,3);
plotSolution(fl, 'flow', 'O2');
title('O2 Mass Fraction');
subplot(2,3,4);
plotSolution(fl, 'flow', 'CH');
title('CH Mass Fraction');
subplot(2,3,5);
plotSolution(fl, 'flow', 'V');
title('Radial Velocity / Radius [s^-1]');
subplot(2,3,6);
plotSolution(fl, 'flow', 'u');
title('Axial Velocity [m/s]');