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-   -   Lack of local thermal equilibrium in porous medium (https://www.cfd-online.com/Forums/cfx/92594-lack-local-thermal-equilibrium-porous-medium.html)

Chander September 19, 2011 11:23

Lack of local thermal equilibrium in porous medium
 
Hi,

I am using CFX ver12.1

I am modeling flow through a porous medium. I have observed that temperature difference between fluid and solid at the length scale of pore is not negligibly small as compared to the temperature difference at the length scale of the major dimension of my computational domain (the ratio of the two is around 0.5)

Now as per CFX/12.1 manual, the energy equation for porous medium assumed local thermal equilibrium and solves for one single representative temperature for porous medium using equivalent thermal conductivity. I am providing to the CXF solver, an equivalent thermal conductivity for this equation.

However, as per my observation in the first paragraph above, my current approach is not entirely correct as the assumption of local thermal equilibrium in porous medium is not valid in my case.

Is there a way to model energy transport in porous media without this assumption in CFX? i.e solve for separate fluid and solid temperatures inside porous medium by solving two separate energy equations for fluid and solid .

I saw some old posts on this forum regarding this issue but could not spot a solution. Thanks for your inputs!

ghorrocks September 19, 2011 19:12

I think this is supported in V13. You can also do it in older versions with lots of additional variables and clever CEL. But why make it hard for yourself, just upgrade to V13 and it should be easy.

Chander September 20, 2011 08:00

@ghorrocks

Thanks for your reply.
I'll certainly try with ver 13.

magarajan84 March 3, 2012 13:37

heat transfer problem
 
Hi everyone,

i am trying to study the heat transfer along with marangoni stress through porous medium which is placed on a solid layer but when i applied heat flux on the porous region i find that there is no heat transfer in the solid zone there is a common wall between the porous and the solid region i don't know what seems to be the problem. i am new to fluent can somebody please guide me through your instructions.

thank you

ghorrocks March 4, 2012 05:07

This is the CFX forum. Try the Fluent forum for questions on fluent.


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