chemical reactions won't happen in microcombustor

Weiqiang Liu · May 7, 2018, 17:26

Hi all,

I am doing a simulation of micro-combustor by importing chemkin mechanism into Fluent. The fuel is methane and air mixture.

Gas phase mechanism is GRI 2.0 and surface mechanism is from deutschmann.

The results of temperature field show the maximum temperature is 550K which is only 50K higher than inlet temperature. Obviously, all exothermic reactions have not happened.

I tried to patch a 2000K high temperature in the whole computation domain to ignite the mixture just like some papers do. however, the results show that it's just like a process of heating the cool incoming mixture and all reactions still can not happen.

I am wondering how can I setup in order to ignite the mixture. Are there any common methods in Fluent to ignite hydrocarbon and air mixtures.

thanks very much!

Weiqiang

LuckyTran · May 7, 2018, 21:46

In addition to temperature, you need to also patch the reaction progress variable.

Weiqiang Liu · May 7, 2018, 21:49

Quote:

Originally Posted by LuckyTran

In addition to temperature, you need to also patch the reaction progress variable.

Hi ，

Thanks very much. I am new to fluent and I cannot very understand what is reaction progress variable. can you give me a more specific hint please?

Weiqiang

May 7, 2018, 17:26	chemical reactions won't happen in microcombustor	#1
Weiqiang Liu Senior Member Weiqiang Liu Join Date: Feb 2018 Posts: 278 Rep Power: 9	Hi all, I am doing a simulation of micro-combustor by importing chemkin mechanism into Fluent. The fuel is methane and air mixture. Gas phase mechanism is GRI 2.0 and surface mechanism is from deutschmann. The results of temperature field show the maximum temperature is 550K which is only 50K higher than inlet temperature. Obviously, all exothermic reactions have not happened. I tried to patch a 2000K high temperature in the whole computation domain to ignite the mixture just like some papers do. however, the results show that it's just like a process of heating the cool incoming mixture and all reactions still can not happen. I am wondering how can I setup in order to ignite the mixture. Are there any common methods in Fluent to ignite hydrocarbon and air mixtures. thanks very much! Weiqiang

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May 7, 2018, 21:46		#2
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,674 Rep Power: 66	In addition to temperature, you need to also patch the reaction progress variable.