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-   -   What is the difference between liquid reactive flow and gas reactive flow? (http://www.cfd-online.com/Forums/main/64565-what-difference-between-liquid-reactive-flow-gas-reactive-flow.html)

James May 14, 2009 11:16

What is the difference between liquid reactive flow and gas reactive flow?
 
Hi All,

I am doing a project on Functionally Graded Materials (FGM). I use a solidification process to generate FGM and find that there is intermetallic compounds in the products. So I think this process involves liquid reactive flow. Now I need to simulate the solidification process with reactive flow.But I found out that almost all of the books and literature deal with gas reactive flow (mostly on combustion). Does anyone know what the difference is between liquid reactive flow and gas reactive flow? How can I transfrom those governing equations for gas reactive flow for use in liquid reactive flow? Does anyone know any books or literature handling liquid reactive flow? Thanks!

James

Ford Prefect May 14, 2009 16:51

Reactive flow in liquids usually involves new phase-formation, whereas gas-reactive flow usually only involves formation of new species in the gas mixture. So assuming that you get some new phase-formation, then the physical data for interfacial properties are usually unknown and there are few (if any) good multiphase methods to deal with reacting flow. If you add solidification to this you have an extremely complex problem.

Fun problem though, so good luck! :)

James May 14, 2009 17:21

Re: What is the difference between liquid reactive flow and gas reactive flow?
 
Hi, Ford:

Thank you for your reply! What do you mean by new phase? Suppose we have liquid Ni and Al, if they react to form NiAl, is NiAl the new phase you mentioned? What is the difference between "new phase" and "new species"? Thank you again!

James

johndorian May 14, 2009 18:02

Quote:

Originally Posted by James (Post 216101)
Hi All,

I am doing a project on Functionally Graded Materials (FGM). I use a solidification process to generate FGM and find that there is intermetallic compounds in the products. So I think this process involves liquid reactive flow. Now I need to simulate the solidification process with reactive flow.But I found out that almost all of the books and literature deal with gas reactive flow (mostly on combustion). Does anyone know what the difference is between liquid reactive flow and gas reactive flow? How can I transfrom those governing equations for gas reactive flow for use in liquid reactive flow? Does anyone know any books or literature handling liquid reactive flow? Thanks!

James

The main difference between reaction in gases and in liquids is the Schmidt number of the flow. Gases have Sc ~ 1, whilst liquids have Sc ~ 700, and this has a significant effect on how chemical species are mixed in the flow. See the following paper - "Scalar mixing and reaction in plane liquid shear layers", P. S. KARASSO M. G. MUNGAL, J. Fluid Mech. (1996), vol. 323, pp. 23-63 for some useful information.

James May 15, 2009 00:34

Re: What is the difference between liquid reactive flow and gas reactive flow?
 
Hi,John:

Thank you for your useful information! I will try to get the paper.

James

Ford Prefect May 15, 2009 07:54

Quote:

Originally Posted by James (Post 216141)
Hi, Ford:

Thank you for your reply! What do you mean by new phase? Suppose we have liquid Ni and Al, if they react to form NiAl, is NiAl the new phase you mentioned? What is the difference between "new phase" and "new species"? Thank you again!

James

Species are part of a mixture, connected to a specific phase. For instance, if you model air you will have two major species, O2 and N2 along with a number of smaller ones. The temperature, pressure and partial pressures of each species will give you the properties of the air phase.

James May 15, 2009 12:14

Re;What is the difference between liquid reactive flow and gas reactive flow?
 
Ford,

Thank you for your reply!

James


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