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-   -   WALL and WALL shadow (http://www.cfd-online.com/Forums/fluent/64193-wall-wall-shadow.html)

duaiduaihu May 2, 2009 04:55

WALL and WALL shadow
 
hello!
I define BC WALL (one side is solid,the other is fluid)in gambit,but i fine WALL and WALL shadow when defining BC in fluent.
can anyone tell me the meaning of wall shadow?

my purpose is to define the temperature of the wall.how should i define the two sides of the interface?


thanks!!!!!!!!!!

contrarian May 2, 2009 05:47

The wall and wall-shadow correspond to the boundaries for the fluid and solid respectively. You can specify independent thermal boundary conditions for the fluid side and the solid side but in most situations you would want to specify a "coupled" boundary condition (heat flux is conserved across the boundary) and specify the thermal boundary conditions (e.g. constant temperature) at the outer wall of the solid region.

Ralf Schmidt May 2, 2009 06:39

see also:

http://www.cfd-online.com/Forums/flu...tml#post214529

duaiduaihu May 2, 2009 20:58

Quote:

Originally Posted by contrarian (Post 214923)
The wall and wall-shadow correspond to the boundaries for the fluid and solid respectively. You can specify independent thermal boundary conditions for the fluid side and the solid side but in most situations you would want to specify a "coupled" boundary condition (heat flux is conserved across the boundary) and specify the thermal boundary conditions (e.g. constant temperature) at the outer wall of the solid region.

thanks!friend!
i still have two questions:
1,wall and wall shadow which is solid BC,and which is fluid BC?
2,i want to define the temperature or heat flux in the solid side ,then should i define the other BC as "couple"?
thanks for your regard!

contrarian May 3, 2009 00:08

You can find the "adjacent cell zone" by opening the BC panel.
However, you cannot specify "coupled" BC at the wall and "temperature" at its shadow. By specifying "coupled", you are stating that the flux on the solid side is the same as the flux on the fluid side. There is no additional input needed at that point. You will need to specify temperature or heat flux boundary condition at the outside wall of the solid. Alternatively you may choose not to model heat transfer in the solid in which case you can as well delete the solid zone.

duaiduaihu May 3, 2009 09:44

Quote:

Originally Posted by contrarian (Post 214970)
You can find the "adjacent cell zone" by opening the BC panel.
However, you cannot specify "coupled" BC at the wall and "temperature" at its shadow. By specifying "coupled", you are stating that the flux on the solid side is the same as the flux on the fluid side. There is no additional input needed at that point. You will need to specify temperature or heat flux boundary condition at the outside wall of the solid. Alternatively you may choose not to model heat transfer in the solid in which case you can as well delete the solid zone.

thanks i will have a try!
my email is daozhenxu@hotmai.com welcome to contact me !
it would be my honnor to know your email!


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