Mohsen Najafi Non-Arrhenius reactions may be modeled in ANSYS Fluent by utilizing the "Reaction Rates and Temperature Dependence" model in the Reaction panel of the Species Model tab. Using a polynomial or a user-defined function, you may provide a temperature-dependent rate coefficient for your response.

Follow these steps to create a non-Arrhenius reaction in Fluent:

1. Select the "Reaction Rates and Temperature Dependence" option in the Reaction panel from the Species Model tab.

2. Enter the temperature-dependent rate coefficient for your reaction. A polynomial or a user-defined function can be used.

3. Indicate the temperature range in which the rate coefficient is valid.

4. Assign the proper reaction sequence and pre-exponential factor.

5. Set up the relevant reactant and product terms if your reaction includes several species.

6. Solve the issue normally, and the non-Arrhenius reaction will be accounted for in the calculations.

I hope this was helpful! Please let me know if you have any more queries.

Hi,

I suggest you see the links on the topic.

https://www.afs.enea.it/project/neptunius/docs/fluent/html/th/node129.htm

https://www.afs.enea.it/project/neptunius/docs/fluent/html/ug/node1078.htm

https://forum.ansys.com/forums/topic/defining-non-arrhenius-form-of-reaction-rates-in-chemical-kinetic-mechanism/

https://alfaproject.ir/wp-content/uploads/2020/07/part-15.pdf

http://users.abo.fi/rzevenho/ansys%20fluent%2018%20tutorial%20guide.pdf

Article Effects of Combustion Model and Chemical Kinetics in Numeric...

Best regards

Mohsen Najafi , In my case also I don't have both the Arrhenius rate and pre-exponential factor. I was trying to follow your steps to solve my problem but can't find this step

'Select the "Reaction Rates and Temperature Dependence" option in the Reaction panel from the Species Model tab. I have attached the pic of the fluent tab. Can you help. Thanks.