Chemical reaction using Eddy Dissipation Model in FLUENT

hyperflow · March 7, 2012, 17:26

Hi all.

I am trying to solve a problem on the gas phase chemical reaction.
Chemical reaction simulate a non-premixed diffusion combustion.
Fuel is multi species including CH4, C2H6 and H2 like decomposed fuel rich gas and oxidizer is O2.
I'd like to use eddy dissipation model in FLUENT.
I think the total number of reaction has to be 3(for CH4, C2H6, H2) and each reaction have to be set to one-step global reaction.
Is this setting right?
Is the total number of reaction for multi-step mechanism of single reaction? or for multi-reaction?
Please help me!

Laci · March 8, 2012, 05:58

You have to decide if you want to simulate one-step skeleton reaction or detailed mechanisms. If you need to investigate flame structure, you should go for the detailed mechanisms and EDC model.
In other cases, the single step reactions should be enough. Since these are really fast reactions I wouldn't expect big difference in the global results of the final compounds between single step and detailed mechanisms.

Sorry, I don't understand these questions:

"Is the total number of reaction for multi-step mechanism of single reaction? or for multi-reaction?"

hyperflow · March 8, 2012, 09:38

Thank you Laci.

Should I have to set to 3 for the total number of reaction due to the CH4, C2H6, H2?

Laci · March 8, 2012, 09:42

You will copy the reactions from the Fluent database right?
Why don't you give it a try as first. As you proceed, you will see (I guess) if your simulation requires more sophisticated detailed reaction mechanisms.
L

hyperflow · March 8, 2012, 09:56

Thanks for fast response.
I will copy only material properties from Fluent database.
Considering fuel is mixture with 12 species produced from fuel rich mixture.
Dominant hydrocarbons are CH4, C2H6, H2.
I think that the each reaction of 3 kinds of fuel(CH4, C2H6, H2) have to be modeled.
I'm considering only one-step global reaction for each fuel.
So, I'd like to know a function of the total number of reaction option.

mohamad3564 · June 11, 2012, 05:54

Hi every body

I have bubble column reactor and I want to simulate species transport and find oxygen transport in it .I want to know how can i set set species transport after initialize my model by mixture model ?and how can i set mas fraction boundry condition ?
best regards

March 7, 2012, 17:26	Chemical reaction using Eddy Dissipation Model in FLUENT	#1
hyperflow New Member SJK Join Date: Mar 2012 Posts: 3 Rep Power: 14	Hi all. I am trying to solve a problem on the gas phase chemical reaction. Chemical reaction simulate a non-premixed diffusion combustion. Fuel is multi species including CH4, C2H6 and H2 like decomposed fuel rich gas and oxidizer is O2. I'd like to use eddy dissipation model in FLUENT. I think the total number of reaction has to be 3(for CH4, C2H6, H2) and each reaction have to be set to one-step global reaction. Is this setting right? Is the total number of reaction for multi-step mechanism of single reaction? or for multi-reaction? Please help me!

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March 8, 2012, 05:58		#2
Laci Member anonym Join Date: Mar 2009 Posts: 65 Rep Power: 17	You have to decide if you want to simulate one-step skeleton reaction or detailed mechanisms. If you need to investigate flame structure, you should go for the detailed mechanisms and EDC model. In other cases, the single step reactions should be enough. Since these are really fast reactions I wouldn't expect big difference in the global results of the final compounds between single step and detailed mechanisms. Sorry, I don't understand these questions: "Is the total number of reaction for multi-step mechanism of single reaction? or for multi-reaction?"

March 8, 2012, 09:38		#3
hyperflow New Member SJK Join Date: Mar 2012 Posts: 3 Rep Power: 14	Thank you Laci. Should I have to set to 3 for the total number of reaction due to the CH4, C2H6, H2?

March 8, 2012, 09:42		#4
Laci Member anonym Join Date: Mar 2009 Posts: 65 Rep Power: 17	You will copy the reactions from the Fluent database right? Why don't you give it a try as first. As you proceed, you will see (I guess) if your simulation requires more sophisticated detailed reaction mechanisms. L

March 8, 2012, 09:56		#5
hyperflow New Member SJK Join Date: Mar 2012 Posts: 3 Rep Power: 14	Thanks for fast response. I will copy only material properties from Fluent database. Considering fuel is mixture with 12 species produced from fuel rich mixture. Dominant hydrocarbons are CH4, C2H6, H2. I think that the each reaction of 3 kinds of fuel(CH4, C2H6, H2) have to be modeled. I'm considering only one-step global reaction for each fuel. So, I'd like to know a function of the total number of reaction option.

June 11, 2012, 05:54		#6
mohamad3564 New Member mohamad Join Date: Jun 2012 Posts: 12 Rep Power: 14	Hi every body I have bubble column reactor and I want to simulate species transport and find oxygen transport in it .I want to know how can i set set species transport after initialize my model by mixture model ?and how can i set mas fraction boundry condition ? best regards