CFD Online Discussion Forums

CFD Online Discussion Forums (
-   FLUENT (
-   -   Low Pressure Surface Coverage (

Natali_Beginner April 25, 2013 12:00

Low Pressure Surface Coverage
Hello guys,
I am recently start working with FLUENT, but I have been working for 10 years in chemistry and combustion. So, this question that I am asking relates just to the FLUENT manipulation.
I am simulating combustion in low pressure. So, surface coverage is low in that pressure that seems reasonable.
However, its low rate value in FLUENT doesn't make sense. In fact, FLUENT doesn't have progress in that after some iterations and the surface coverage remains unchanged.
Do you have any suggestion how to get rid of that?
I am entering some coverage-dependent reaction parameters but it doesn't work.
I really appreciate if you help me since I am so stuck on that :(

Natali_Beginner April 25, 2013 19:46

Hey Guys,
I am really praying somebody helps me from this annoying problem.

Natali_Beginner April 26, 2013 14:32

Any Help?
I am really in problem.

Parisa_Khiabani April 26, 2013 14:39

Hey Natali,
There is an option in the surface chemistry as coverage dependent reaction. Did you check that?
By default, its values are zero. maybe you want to change them to a realistic value.
Did you check the Knudsen number in your problem? Be careful that the knudsen number not become very high, say 0.1


Natali_Beginner April 26, 2013 14:50

Thanks Parisa,
Yes, I tried that too. However, it doesn't work although at the beginning just a little bit more progress in coverage is seen, but it will be stopped.
the Knudsen number is in the range of continuum approach. So it shouldn't have any problem.
I am really confused and exhausted about this problem.


Parisa_Khiabani April 26, 2013 14:56

So, do you have any estimate about the real times or values?
The reactions reach to equilibrium soon in low pressure and maybe you get correct results.

Natali_Beginner April 26, 2013 15:16

I don't have exact values to compare.
But I know that the surface coverage should keep changing.

Parisa_Khiabani April 26, 2013 15:21

Can you send me your case?

Parisa_Khiabani April 26, 2013 15:23

I sent you already my Email.

Natali_Beginner April 26, 2013 15:26

Check your Email, please.

Natali_Beginner April 28, 2013 02:19

Hello guys,
I am seriously praying somebody can help me to solve this issue. This seems very annoying and boring.

All times are GMT -4. The time now is 06:04.