chemkin thermo data

Weiqiang Liu · September 17, 2018, 10:05

Hi all,

I have two thermo data file at hand. one is from GRI 3.0 thermo data and the other is from n-dodecane thermo developed by Hai Wang.

the former has 14 fitting coefficients and the latter has 15 fitting coefficients. I looked up chemkin user manual and found that normally there are 7 coefficients for the upper temperature range and 7 coefficients for the lower temperature range and the total number of coefficients is 14. So what is the problem with 15 coefficients?

thanks.

LuckyTran · September 17, 2018, 12:27

I have heard tales of 15 coefficient thermo formulations used for by other non-chemkin mechanisms. These usually come with instructions that say "delete coefficient 15 because it is not used by chemkin." Maybe that's what you have come across.

Weiqiang Liu · September 17, 2018, 15:03

Quote:

Originally Posted by LuckyTran

I have heard tales of 15 coefficient thermo formulations used for by other non-chemkin mechanisms. These usually come with instructions that say "delete coefficient 15 because it is not used by chemkin." Maybe that's what you have come across.

OK， so you think I should delete coefficient 15 so that the thermo data can be imported into fluent as chemkin format thermo data?

LuckyTran · September 17, 2018, 16:16

I think you should look carefully at what thermo.dat you actually have because it's clearly not a chemkin one. I don't know Hai Wang and I have no clue what you have. For all I know, the 15th coefficient could be their bank account number. And I have no clue what the mapping is from one to the other, maybe you need to delete the 1st coefficient, or the 4th. No clue.

Weiqiang Liu · September 19, 2018, 12:23

Quote:

Originally Posted by LuckyTran

I think you should look carefully at what thermo.dat you actually have because it's clearly not a chemkin one. I don't know Hai Wang and I have no clue what you have. For all I know, the 15th coefficient could be their bank account number. And I have no clue what the mapping is from one to the other, maybe you need to delete the 1st coefficient, or the 4th. No clue.

thanks very much. so Can I built my own thermo file by copy data in some kind of database. Do you know where can I get the thermo data of specific species I want? NASA thermo data?

September 17, 2018, 10:05	chemkin thermo data	#1
Weiqiang Liu Senior Member Weiqiang Liu Join Date: Feb 2018 Posts: 278 Rep Power: 9	Hi all, I have two thermo data file at hand. one is from GRI 3.0 thermo data and the other is from n-dodecane thermo developed by Hai Wang. the former has 14 fitting coefficients and the latter has 15 fitting coefficients. I looked up chemkin user manual and found that normally there are 7 coefficients for the upper temperature range and 7 coefficients for the lower temperature range and the total number of coefficients is 14. So what is the problem with 15 coefficients? thanks.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
problem with exporting data to Tecplot	v.jab	OpenFOAM Post-Processing	2	January 11, 2017 09:56
[OpenFOAM] saving data in paraview	aylalisa	ParaView	3	May 31, 2014 12:38
[General] Warping Cells by Vectors?	ronwelty	ParaView	10	April 29, 2014 06:52
[Commercial meshers] fluentMeshToFoam multidomain mesh conversion problem	Attesz	OpenFOAM Meshing & Mesh Conversion	12	May 2, 2013 11:52
How to update polyPatchbs localPoints	liu	OpenFOAM Running, Solving & CFD	6	December 30, 2005 18:27

September 17, 2018, 12:27		#2
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,761 Rep Power: 66	I have heard tales of 15 coefficient thermo formulations used for by other non-chemkin mechanisms. These usually come with instructions that say "delete coefficient 15 because it is not used by chemkin." Maybe that's what you have come across.

September 17, 2018, 16:16		#4
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,761 Rep Power: 66	I think you should look carefully at what thermo.dat you actually have because it's clearly not a chemkin one. I don't know Hai Wang and I have no clue what you have. For all I know, the 15th coefficient could be their bank account number. And I have no clue what the mapping is from one to the other, maybe you need to delete the 1st coefficient, or the 4th. No clue.