#################################################################### # # Tutorial 2: Using your own reaction mechanism files # #################################################################### # You can build a gas mixture object by importing element, species, # and reaction definitions from input files in supported # formats. Currently, two formats are supported. # Importing CK-format files # ------------------------- # By 'CK format', we mean the input file format developed for use # with the Chemkin-II software package. [See R. J. Kee, # F. M. Rupley, and J. A. Miller, Sandia National Laboratories # Report SAND89-8009 (1989).] # These files contain no equation of state information, since an # ideal gas mixture is implicitly assumed. (Chemkin-II does not # handle non-ideal gases.) Therefore, it is appropriate in Cantera # to build from them objects that represent ideal gas # mixtures. This is done using function IdealGasMix: from Cantera import * gas1 = IdealGasMix('mech.inp') # This statement creates a mixture that implements GRI-Mech 3.0, # much like function GRI30 does. File 'gri30.inp' is in the 'data' # directory. Under Windows, this directory # # Cantera always looks in the local directory first, however. So if # you have a file of the same name in the local directory, # it will be used instead. # The CK file format specification does not require that all # species data be contained in the file. Missing species # definitions (usually called 'thermo' data but in fact defining # all properties of the species, including name, phase, and # elemental composition) are to be looked up in a second # 'thermodynamic database' file. To create the object from an # incomplete input file, give both file names as arguments: gas2 = IdealGasMix('air.inp','nasathermo.dat') # The CK file specification does not include transport data for the # species. These too are taken from an external database. If you # need transport properties, include the transport file name and # transport model to implement as follows: gas3 = IdealGasMix(src = 'gri30.inp', transport_db = 'gri30_tran.dat', transport = 'Multi') # Allowable values for the transport model are 'Multi' and # 'Mix'. If the model is omitted, 'Mix' is assumed. # Importing CTML files # ------------------- # Cantera can also read input files in an XML-based format called # 'CTML' (Cantera Markup Language). These input files are complete, # and do not require auxiliary database files for either thermodynamic # or transport properties. To import a CTML file, simply give the file # name in the call to IdealGasMix: gxml = IdealGasMix('gri30.xml') # Cantera determines the file format by examining its contents. A # conversion utility is available that converts CK-format files into # CTML.