[Weiqiang Liu]

Hi all,

I am doing a catalytic combustion simulation with fluent. The gas phase and surface face mechanisms, thermodynamic and transport are imported into fluent in chemkin format.

I posted many threads before about the divergence and failure of ignition. Unfortunately, I am not able to solve these problems until yesterday I found a similar case in a tutorial book.

In that case, the gas phase mechanism is ignored just like a lot of literature do. Also, thermodynamic and transport data are left blank in that case.

I followed that case and reproduced the results in a published paper successfully. Then I tried to import my thermodynamic and transport data and divergence happened again.

I have two questions regarding to this problem.
1. if I don't import any thermodynamic and transport data, fluent will use thermodynamic and transport data in its database by default?

2. why the imported thermodynamic and transport data caused divergence and the default value in fluent database not?

Thanks very much!

weiqiang

[LuckyTran]

Originally Posted by Weiqiang Liu

1. if I don't import any thermodynamic and transport data, fluent will use thermodynamic and transport data in its database by default?

Go to material properties and you can see what properties are needed and what is being used.


If you don't have any volumetric reactions then why do you even need thermo and transport data? What are you even modeling?

[Weiqiang Liu]

Originally Posted by LuckyTran

Go to material properties and you can see what properties are needed and what is being used.


If you don't have any volumetric reactions then why do you even need thermo and transport data? What are you even modeling?

I am doing a micro-channel simulation. I removed all the gas phase reactions just like a lot of literature do. However I still need thermodynamic and transport data of gas phase species because I need to model the desorption and adsorption process of gas species from catalytic surface.

I mean fluent would use default values of gas thermodynamic and transport in its database if I do not import any chemkin gas thermo and transport file.

[Weiqiang Liu]

Hi all,

I figured out how to use external thermo and transport data and got exactly the same results in literature.

Thanks