example_utils.h (Source)

// This file is part of Cantera. See License.txt in the top-level directory or

#ifndef CT_EXAMPLE_UTILS_H
#define CT_EXAMPLE_UTILS_H

#include "cantera/base/Array.h"
#include "cantera/base/plots.h"

// Save the temperature, density, pressure, and mole fractions at one
// time
template<class G, class A>
void saveSoln(int i, double time, const G& gas, A& soln)
{
soln(0,i) = time;
soln(1,i) = gas.temperature();
soln(2,i) = gas.density();
soln(3,i) = gas.pressure();
gas.getMoleFractions(&soln(4,i));
}

template<class G, class A>
void saveSoln(double time, const G& gas, A& soln)
{
soln.resize(soln.nRows(), soln.nColumns() + 1);
int back = soln.nColumns() - 1;
soln(0,back) = time;
soln(1,back) = gas.temperature();
soln(2,back) = gas.density();
soln(3,back) = gas.pressure();
int nsp = gas.nSpecies();
for (int k = 0; k < nsp; k++) {
soln(4+k,back) = gas.moleFraction(k);
}
}

template<class G, class V>
void makeDataLabels(const G& gas, V& names)
{
int nsp = gas.nSpecies();
names.resize(nsp + 4);
names[0] = "time (s)";
names[1] = "Temperature (K)";
names[2] = "Density (kg/m3)";
names[3] = "Pressure (Pa)";
int k;
for (k = 0; k < nsp; k++) {
names[4+k] = gas.speciesName(k);
}
}

template<class G, class A>
void plotSoln(const std::string& fname, const std::string& fmt,
const std::string& title, const G& gas, const A& soln)
{
std::vector<std::string> names;
makeDataLabels(gas, names);
writePlotFile(fname, fmt, title, names, soln);
}

#endif

kinetics1.cpp (Source)

/*!
* @file kinetics1.cpp
*
* Zero-dimensional kinetics
*
* This example simulates autoignition of hydrogen in a constant pressure
* reactor and saves the time history to files that can be used for plotting.
*
* Keywords: combustion, reactor network, ignition delay, saving output
*/

// This file is part of Cantera. See License.txt in the top-level directory or

#include "cantera/zerodim.h"
#include "cantera/thermo/IdealGasPhase.h"
#include "cantera/numerics/Integrator.h"
#include "example_utils.h"

using namespace Cantera;
using std::cout;
using std::endl;

int kinetics1(int np, void* p)
{
cout << "Constant-pressure ignition of a "
<< "hydrogen/oxygen/nitrogen"
" mixture \nbeginning at T = 1001 K and P = 1 atm." << endl;

// create an ideal gas mixture that corresponds to OH submech from GRI-Mech 3.0
auto sol = newSolution("h2o2.yaml", "ohmech", "None");
auto gas = sol->thermo();

// set the state
gas->setState_TPX(1001.0, OneAtm, "H2:2.0, O2:1.0, N2:4.0");
int nsp = gas->nSpecies();

// create a reactor
IdealGasConstPressureReactor r;

// 'insert' the gas into the reactor and environment.  Note
// that it is ok to insert the same gas object into multiple
// reactors or reservoirs. All this means is that this object
// will be used to evaluate thermodynamic or kinetic
// quantities needed.
r.insert(sol);

double dt = 1.e-5; // interval at which output is written
int nsteps = 100; // number of intervals

// create a 2D array to hold the output variables,
// and store the values for the initial state
Array2D soln(nsp+4, 1);
saveSoln(0, 0.0, *(sol->thermo()), soln);

// create a container object to run the simulation
// and add the reactor to it
ReactorNet sim;

// main loop
clock_t t0 = clock(); // save start time
for (int i = 1; i <= nsteps; i++) {
double tm = i*dt;
cout << "time = " << tm << " s" << endl;
saveSoln(tm, *(sol->thermo()), soln);
}
clock_t t1 = clock(); // save end time

// make a Tecplot data file and an Excel spreadsheet
std::string plotTitle = "kinetics example 1: constant-pressure ignition";
plotSoln("kin1.dat", "TEC", plotTitle, *(sol->thermo()), soln);
plotSoln("kin1.csv", "XL", plotTitle, *(sol->thermo()), soln);

// print final temperature and timing data
double tmm = 1.0*(t1 - t0)/CLOCKS_PER_SEC;
cout << " Tfinal = " << r.temperature() << endl;
cout << " time = " << tmm << endl;
cout << " number of residual function evaluations = "
<< sim.integrator().nEvals() << endl;
cout << " time per evaluation = " << tmm/sim.integrator().nEvals()
<< endl << endl;
cout << "Output files:" << endl
<< "  kin1.csv    (Excel CSV file)" << endl
<< "  kin1.dat    (Tecplot data file)" << endl;

return 0;
}

int main()
{
try {
int retn = kinetics1(0, 0);
appdelete();
return retn;
} catch (CanteraError& err) {
// handle exceptions thrown by Cantera
std::cout << err.what() << std::endl;
cout << " terminating... " << endl;
appdelete();
return -1;
}
}