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-   -   Modeling the mixing of air and kerosene in a flow channel (http://www.cfd-online.com/Forums/cfx/102910-modeling-mixing-air-kerosene-flow-channel.html)

StefanG June 6, 2012 03:31

Modeling the mixing of air and kerosene in a flow channel
 
Dear CFD-Online Community,


I have the following task to be solved:


I have a flow channel with a combustion chamber in which I want to inject Jet A kerosene (gas phase) by an injector.
The medium in the flow channel is Air Ideal Gas.


My aim is to study the mixing behavior of the kerosene with the air in the flow channel. The results from my calculations (without burning) will be compared with results from the test bench.
Then several cases will be studied by simulations and the most promising will be realized at the test bench with burning.

From the simulations we hope to see the kerosene distribution and mixing the flow chamber.


Unfortunately I am not sure how to model this case.


In a first step I solved the flow field in the flow channel without injection of the kerosene.
Now I want to use these results as the initial flow field with injection of the kerosene.


To model this, I created a new material in CFX consisting of the components Air Ideal Gas and Jet A. As mixture properties I set Ideal mixture.
In fluid models I set constraint for the Air Ideal Gas component and transport equation for the Jet A component.


At the Inlet for Air I set the mass fraction of Jet A equal to zero and at the kerosene inlet equal to one.


My question is now weather this approach is correct and sufficiently or if someone has other suggestion to model my problems,
for example using more complex modelings like multicomponent multiphase models and so on.

Which other possibilities in CFX could be interesting for my problem?

Thank you very much in advance for your support!

Best greetings,
Stefan

ghorrocks June 6, 2012 06:13

This does not sound like a multiphase model as everything appears to be in the gaseous phase. Sounds like it is a single phase multicomponent mixture model to me.

StefanG June 8, 2012 04:57

Quote:

Originally Posted by ghorrocks (Post 364993)
This does not sound like a multiphase model as everything appears to be in the gaseous phase. Sounds like it is a single phase multicomponent mixture model to me.

Yes it does, but I am not sure about the limits about this model.
If understood right, the multicomponent model assumes that the two species are mixed on the molecular level and the share all flow properties (same pressure, velocities, temperature and so on).

Will I be able to capture the turbulent mixing of air and kerosene with this model?


Greetings,

Stefan

ghorrocks June 11, 2012 20:21

Quote:

If understood right, the multicomponent model assumes that the two species are mixed on the molecular level and the share all flow properties (same pressure, velocities, temperature and so on).
You are correct.

Quote:

Will I be able to capture the turbulent mixing of air and kerosene with this model?
Yes.


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