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-   -   Interface between fluid domain and porous domain (https://www.cfd-online.com/Forums/cfx/68024-interface-between-fluid-domain-porous-domain.html)

windhair September 3, 2009 10:51

Interface between fluid domain and porous domain
 
I'm building a model with a free fluid domain and a porous domain, the upper domain is free flow, where the lower is porous media, the flow coming from the left side of upper domain. It is incompressible laminar flow.

The velocity component normal to the interface is shown in the attached figure
http://i34.photobucket.com/albums/d116/windhair/v.png

my question is why there are two high velocity region is this result, it looks unreasonable, how can I correct it?

Thanks

John September 3, 2009 12:19

not converged results?

windhair September 4, 2009 03:46

Quote:

Originally Posted by John (Post 228450)
not converged results?

I made another run last night, I think it is converged with
Code:

|      Equation      | Rate | RMS Res | Max Res |  Linear Solution |
 +----------------------+------+---------+---------+------------------+
 | U-Mom                | 0.97 | 9.9E-09 | 5.1E-08 |      7.4E-01  ok|
 | V-Mom                | 0.97 | 7.5E-10 | 2.0E-08 |      1.3E-01  ok|
 | W-Mom                | 0.97 | 3.9E-10 | 1.4E-08 |      2.5E-01  ok|
 | P-Mass              | 0.97 | 1.2E-10 | 1.4E-09 |  5.4  7.2E-02  OK|
 +----------------------+------+---------+---------+------------------+

http://i34.photobucket.com/albums/d116/windhair/v1.png

The results show the approaching of the two high velocity region, that looks better, but I'm still wondering about the correctness of this velocity jumping.

ghorrocks September 4, 2009 08:01

Are you sure you have an adequately mesh independent solution? Have you looked at the velocity vectors to see what direction the flow is going? Have you checked the documentation about how velocities in porous regions are handled?

windhair September 10, 2009 08:12

With refined mesh, the result is better, bu still some problem with interface between porous media and fluid domain.
http://i34.photobucket.com/albums/d1...air/Chart2.png
http://i34.photobucket.com/albums/d116/windhair/v2.png

I can not understand the jump of velocity component normal to the interface, when there are only straight forward flow in the upper fluid domain.

nkwtan September 5, 2013 20:45

I have same problem I checked both to be porous and both be fluid. I don't see any jump in the interface. however when I select one porous and one fluid. i see this jump. i don't know why this happen. :confused:


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