[kriete]

Hello,
can somebody who is familiar with the CHEMKIN file format please help with the following problem?

I am trying to use the file [1] as thermo.dat input for the combustion solver. Although [2] says that the file is in CHEMKIN format, there seems to be at least one major incompatibility compared to the format description at [3]:

For example, lines 34-38 of [1] read:

oh         8/12/99 thermh   1o   1    0    0g   300.000  5000.000 1357.000    01
 2.62599754e+00 1.31992406e-03-3.59724670e-07 4.25630800e-11-1.82048016e-15    2
 4.12085374e+03 7.10667307e+00 3.43586219e+00 2.02235804e-04-1.13546412e-07    3
 2.42445149e-10-7.43651031e-14 3.74321252e+03 2.45014127e+00                   4

Columns 74...80 of line 34 are "0....01", although these colums must be "......1" according to [3]. What is the meaning of the additional digits? If I replace the unrecognized digits (here and elsewhere) with spaces, the reaction timing is wrong.

Anyone familiar with the CHEMKIN format, who can help?

Thank you
Helge

[1] https://www-pls.llnl.gov/data/docs/s...symp_therm.txt
[2] https://www-pls.llnl.gov/?url=scienc...uced_mechanism
[3] http://www2.galcit.caltech.edu/EDL/p...s/chemkin.html

[brugiere_olivier]

Hi,

You can try to use libOpensmoke and the flamlet solvers developped by Tobias

Regards

[dkxls]

I cannot really help you, but I can confirm the problem.

Reading CHEMKIN mechanisms or thermo files with OpenFOAM is an adventures exercise.
I barely got any of the mechanisms from LLNL to work with OpenFOAM.

A workaround that I used for some smaller mechanisms was to convert the CHEMKIN files to OpenFOAM-format with

chemkinToFoam

and fix the occurring errors by hand. Apparently this isn't a really good solution. Also keep in mind that the CHEMKIN lexer is always the same.
On the plus side you get a "human readable" mechanism/thermo file that works for sure with OpenFOAM.


And maybe a last note concerning the thermo files: The common temperature of the two Cp/h/s polynomial (Tcommon) needs to be the same for all species. If this is not the case for your thermo data you need to refit the polynomials.

Cheers,
Armin

[dkxls]

Oh and you can find a quite good description of the thermo data, i.e. NASA or JANAF polynomials, here:
http://www.me.berkeley.edu/gri_mech/data/nasa_plnm.html