add free H2/air flame example

Cantera/python/examples/flames/free_h2_air.py

@@ -0,0 +1,84 @@
+#
+# A freely-propagating premixed hydrogen/air flame
+#
+#
+from Cantera import *
+from Cantera.OneD import *
+from Cantera.OneD.FreeFlame import FreeFlame
+
+################################################################
+#
+# parameter values
+#
+p          =   OneAtm          # pressure
+tin        =   300.0                # unburned gas temperature
+
+rxnmech    =  'ohn.cti'            # reaction mechanism file
+mix        =  'gas'              # gas mixture model
+comp       =  'H2:2, O2:1, N2:3.76'  # premixed gas composition
+
+# The solution domain is chosen to be 50 cm, and a point very near the
+# downstream boundary is added to help with the zero-gradient boundary
+# condition at this boundary.
+initial_grid = [0.0, 0.001, 0.02, 0.04, 0.07, 0.099, 0.1]  # m
+
+tol_ss    = [1.0e-5, 1.0e-13]        # [rtol atol] for steady-state
+                                    # problem
+tol_ts    = [1.0e-4, 1.0e-9]        # [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 = IdealGasMix(rxnmech, mix)
+
+# set its state to that of the unburned gas at the burner
+gas.set(T = tin, P = p, X = comp)
+
+f = FreeFlame(gas = gas, grid = initial_grid)
+
+# set the properties at the inlet
+f.inlet.set(mole_fractions = comp, temperature = tin)
+
+f.set(tol = tol_ss, tol_time = tol_ts)
+f.setMaxJacAge(5, 10)
+f.set(energy = 'off')
+#f.init()
+f.showSolution()
+
+f.solve(loglevel, refine_grid)
+
+f.setRefineCriteria(ratio = 5.0, slope = 0.05, curve = 0.005, prune = 0.0)
+f.set(energy = 'on')
+f.solve(loglevel,refine_grid)
+
+f.save('freeflame1.xml')
+f.showSolution()
+
+
+# write the velocity, temperature, and mole fractions to a CSV file
+z = f.flame.grid()
+T = f.T()
+u = f.u()
+V = f.V()
+fcsv = open('freeflame1.csv','w')
+writeCSV(fcsv, ['z (m)', 'u (m/s)', 'V (1/s)', 'T (K)', 'rho (kg/m3)']
+         + list(gas.speciesNames()))
+for n in range(f.flame.nPoints()):
+    f.setGasState(n)
+    writeCSV(fcsv, [z[n], u[n], V[n], T[n], gas.density()]
+             +list(gas.moleFractions()))
+fcsv.close()
+
+print 'solution saved to freeflame1.csv'
+print 'flamespeed = ',u[0],'m/s'
+f.showStats()
+

Cantera/python/examples/flames/ohn.cti

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+#
+# see http://reaflow.iwr.uni-heidelberg.de/~Olaf.Deutschmann/ for 
+# more about this mechanism
+#
+#---------------------------------------------------------------------!
+#***********************************************************************
+#****                                                                  *
+#****     CH4-O2 SURFACE MECHANISM  ON PT                              *
+#****                                                                  *
+#****     Version 1.2   November  1995                                 *
+#****                                                                  *
+#****     O. Deutschmann, IWR, Heidelberg University, Germany          *
+#****                                                                  *
+#****     Kinetic data:                                                *
+#****      k = A * T**b * exp (-Ea/RT)         A          b       Ea   *
+#****                                       (cm,mol,s)    -      J/mol *
+#****                                                                  *
+#****                                                                  *
+#***********************************************************************
+#
+#  Ref:- 1.) Deutschman et al., 26th Symp. (Intl.) on Combustion,1996
+#            pp. 1747-1754
+#----------------------------------------------------------------------
+#
+#  Converted to Cantera format 
+#  by ck2cti on Thu Aug 21 07:58:45 2003
+#
+#----------------------------------------------------------------------
+
+units(length = "cm", time = "s", quantity = "mol", act_energy = "J/mol")
+
+
+#
+# This definition extracts the O/H/N submechanism from GRI-Mech 3.0
+
+ideal_gas(name = "gas",
+          elements = "O H N",
+          species = """gri30: all""",
+          transport = 'Mix',
+          reactions = 'gri30: all',
+          options = ['skip_undeclared_elements',
+                     'skip_undeclared_species'],
+          initial_state = state(temperature = 300.0, pressure = OneAtm,
+                                mole_fractions = 'H2:2, O2:1, N2:3.76')
+          )
+