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-   -   import chemkin mechanism into fluent (https://www.cfd-online.com/Forums/fluent/206349-import-chemkin-mechanism-into-fluent.html)

Weiqiang Liu September 4, 2018 11:20

import chemkin mechanism into fluent
 
1 Attachment(s)
Hi all ,

I am trying to import a n-dodecane mechanism into fluent. However, the error occurs like 'error while trying to read species at line no. 15'

I opened the mechanism file in txt format and found line no. 15 has the species below:

CH2* CH3 CH4 HCO CH2O

I guess it's CH2* that causes this error. So I changed this species into CH2(S) and error still happens.

I wonder how can this species be changed so error won't happen?

thanks a lot

Micael September 4, 2018 13:00

may be just remove asterisk and add a letter, like aCH2 (in order to still distinguish from CH2 if such species is already included). Obviously you got to change it everywhere in the mechanism reactions as well as in thermo and transport file.

Weiqiang Liu September 4, 2018 13:38

Quote:

Originally Posted by Micael (Post 705299)
may be just remove asterisk and add a letter, like aCH2 (in order to still distinguish from CH2 if such species is already included). Obviously you got to change it everywhere in the mechanism reactions as well as in thermo and transport file.

thanks very much. I'll try this

Weiqiang Liu September 4, 2018 14:17

Quote:

Originally Posted by Micael (Post 705299)
may be just remove asterisk and add a letter, like aCH2 (in order to still distinguish from CH2 if such species is already included). Obviously you got to change it everywhere in the mechanism reactions as well as in thermo and transport file.

hello,

I changed CH2* into aCH2 and the corresponding species in reactions, thermo and transport file. Still same error occurs. The version of Fluent I am using is Ansys Fluent 18.2.

have you ever met this error before?

thanks

Micael September 4, 2018 14:38

can you attach mechanism file

Weiqiang Liu September 4, 2018 14:42

Quote:

Originally Posted by Micael (Post 705316)
can you attach mechanism file

hello,

mechanism has been attached .thanks

Weiqiang Liu September 5, 2018 11:38

Quote:

Originally Posted by Micael (Post 705316)
can you attach mechanism file

hello,

I changed the CH2* into CH2star in all mechanism , thermo and transport file. the error about mechanism does not occur. however, it says invalid thermo data about CH2star.

it's very strange.

shyamal September 18, 2019 03:57

Hello Weiqiang Liu,

Could you able figure out the error? I am facing this error "Unexpected word, , in CHEMKIN file, at line. no. 1". Wish you can give some input.

Weiqiang Liu September 18, 2019 14:58

Quote:

Originally Posted by shyamal (Post 744932)
Hello Weiqiang Liu,

Could you able figure out the error? I am facing this error "Unexpected word, , in CHEMKIN file, at line. no. 1". Wish you can give some input.

it means you used wrong word at line no.1 . Just check the rules in CHEMKIN user manual. You will find the error

shyamal September 19, 2019 02:20

The line is commented and it has nothing in it. This may be due to hidden new line command (\n) in the chemkin.inp which is not explicitly showing. I have also tried with reducing the chemkin to only two number of reactions, where it shows the same error.

Weiqiang Liu September 19, 2019 12:02

Quote:

Originally Posted by shyamal (Post 744992)
The line is commented and it has nothing in it. This may be due to hidden new line command (\n) in the chemkin.inp which is not explicitly showing. I have also tried with reducing the chemkin to only two number of reactions, where it shows the same error.

well, where did you get that mechanism file? you should try to download those files from official web of those authors or from chemkin installation folder

shyamal September 19, 2019 13:01

Dear sir,

There is another research flow in our group, they work on this kind of detail gas-phase chemistry and their reduction. I get the chemkin.inp and thermo.dat files from there. This is for ethylene flame. These files work very well with their Chemkin simulations. Thank you.

Weiqiang Liu September 19, 2019 13:56

Quote:

Originally Posted by shyamal (Post 745038)
Dear sir,

There is another research flow in our group, they work on this kind of detail gas-phase chemistry and their reduction. I get the chemkin.inp and thermo.dat files from there. This is for ethylene flame. These files work very well with their Chemkin simulations. Thank you.

yes, it happens sometimes. For my case, I replaced my mechanism form the author's website. Then everything is right and error never happens again. I don't know why.

However, there might be some difference between chemkin files and fluent files.

dli September 28, 2019 07:23

Quote:

Originally Posted by Weiqiang Liu (Post 705399)
hello,

I changed the CH2* into CH2star in all mechanism , thermo and transport file. the error about mechanism does not occur. however, it says invalid thermo data about CH2star.

it's very strange.

Dear Liu,
Have you figured out what exactly the problem? I also met this type of erro,also I change the name of the "wrong " species in all the species block,thermo block and reaction block , it still doesn't work.

Weiqiang Liu September 28, 2019 09:35

Quote:

Originally Posted by dli (Post 745758)
Dear Liu,

Have you figured out what exactly the problem? I also met this type of erro,also I change the name of the "wrong " species in all the species block,thermo block and reaction block , it still doesn't work.



hi,

If I remember right, I changed all CH2* into CH2(s). Than I copied thermo data of CH2(s) from GRI 3.0 database. Finally everything worked.

You can try that

Best

Mohammed Alsaffar April 1, 2020 07:02

what is the name of this group plz.?

Mohammed Alsaffar April 1, 2020 07:04

Quote:

Originally Posted by shyamal (Post 745038)
Dear sir,

There is another research flow in our group, they work on this kind of detail gas-phase chemistry and their reduction. I get the chemkin.inp and thermo.dat files from there. This is for ethylene flame. These files work very well with their Chemkin simulations. Thank you.

what is the name of this group plz.?

Weiqiang Liu April 18, 2020 06:23

Quote:

Originally Posted by Mohammed Alsaffar (Post 763805)
what is the name of this group plz.?

hi
Bro, I don't know the group


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