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-   -   Multiphase air and exhaust gas mixture (http://www.cfd-online.com/Forums/star-ccm/92722-multiphase-air-exhaust-gas-mixture.html)

hamzamotiwala September 23, 2011 03:56

Multiphase air and exhaust gas mixture
 
hey everyone,

I am trying to simulate a high pressure exhaust gas recirculation system. I need to define multiphase flow here. The main inlet would be air and the ÉGR inlet would have exhaust gas. I checked the available materials for the multiphase model in starccm and could not find anything that would resemble exhaust gas. I am using unsteady segregated flow model along with turbulence and eulerian multiphase.

Can anyone help me in some way define exhaust gases for this model? Any help would be appreciated.

Thanks,
Hamza

RobertB September 23, 2011 08:24

What you need to define is a multi component problem not a multi phase one. All the components are gases. You define the various gases needed then specify their concentration at the various inlets.

hamzamotiwala September 26, 2011 08:16

Thanks Robert! I will try that out and let you know. :)

hamzamotiwala September 27, 2011 07:43

Hello Robert,

I tried using the multi-component gas model and I was not able to give in the exact proportions of the components. I also just want to specify this mixture for EGR inlet and I want air for the main inlet. I could not find a way to do this either.

One thing I found is that I can define a different continuum for both the gases but I dont think it will mix anything and it might not even work if I define the egr as a different region.

Do you know any other work around for this problem?

Thanks,
Hamza

RobertB September 27, 2011 16:11

Why could you not specify the components? You build a multi component gas mixture in the physics. At each inlet you can specify the mass fraction of each component.

What more do you need to specify?

hamzamotiwala September 28, 2011 05:38

Hey Robert,

Thanks. I completelty overlooked the mass fraction thing and it was by default set on constant. Anyways I fixed it and am running the simulation now. Hope for some good results.

Thanks again,
Hamza


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