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buxtsued July 5, 2011 15:20

reduced version of GRI 3.0 Mechanism
I wish to simulate a combustion in Fluent 13.0 with the "gri 3.0"-mechanism. After importing it in chemkin format (with the appropriate thermo.dat) and setting to pdf transport model, there appears a message "Maximum of 50 solved species allowed. Use Dimension Reduction instead." (gri 3.0 has 53 spesies). I have tried to reduce the number of spesies to 50 using the "Dimension Reduction" option (choosing out varios three spesies from the list "i wish not to take part"), but it doesn't work, nevertheless. In the 'Spesies Model' dialog box the number of volumetric spesies can be seen under "reduced-dimension-mixture", which remains 53 (in spite of using the dimension reduction option).
Do anybody know how to use a 50-species (e.g. reduced) version of GRI-Mech 3.0 in Fluent???

Thanks, buxtsued

Mica July 13, 2011 04:41

Hey buxtsued,

I'm working with a reduced Grimech mechanism. DO the following:
Open the chemkin-file you want to import in any text-editor. You can quote out the following information in a line by "!" (As done in the header)
Quote out or delete the most abundant species. In my case these are AR C3H7 and C3H8. Remember to quote out AR in the elements list too.
Search all reactions containig these species and quote them out. You can also reorder your species and set N2 at the last place. This is appropriate for combustion in air, then you dont have to specify the fraction of N2 in Fluent, since it is just the rest.


buxtsued July 13, 2011 19:47

Hi Mica,
i have tried to do so, but there is still the same problem. Did you use the "Dimension Reduction" function after importing your modified chemkin mechanism?
Maybe i didnt modify the gri3.0-file correctly. Could you eventually send me your modified mechanism?:)


Mica July 14, 2011 02:49

1 Attachment(s)
Here it is...

buxtsued July 14, 2011 11:01

It works. Thanks for your help.

dpfrz November 21, 2014 10:33

GRI 3.0 Mechanism
Hey guys, its crucial that I use GRI 3.0 Mechanism for my simulations but unfortunately I think I will need a CHEMKIN-CFD license to do so in Fluent. Is there another way to do this without a license or even find the license somewhere?

Thank you for your time!

jp279 July 23, 2015 08:19

After importing the Chemkin file for mechanism and transport, fluent takes very long for each iteration (Steady State).
Can anyone suggest any speed up criteria where I can avoid solving for a few less important species?
(Currently solving for 50 species)

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