CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   CFX (http://www.cfd-online.com/Forums/cfx/)
-   -   GGI (General Grid Interface) Connections (http://www.cfd-online.com/Forums/cfx/71732-ggi-general-grid-interface-connections.html)

feixiangniao January 13, 2010 08:34

GGI (General Grid Interface) Connections
 
hello,everyone.
In the help-document of GGI (General Grid Interface) Connections, GGI connections permit non-matching of node location, element type, surface extent, surface shape and even non-matching of the flow physics across the connection.
So i think the GGI Connections is the overlapping surfaces, and if the size of the connection region for one side is different to the second side, the connection will be automatically made between the mutually overlapping surfaces.
And then i define a solid-solid interface.but the side_1 is bigger than the side_2.
But at the ANSYS CFX Output File (GGI Runs), it shows:

Domain Interface Name : Domain Interface 7
Non-overlap area fraction on side 1 = 7.21E-05
Non-overlap area fraction on side 2 = 6.44E-08
Domain Interface Name : Domain Interface 6
Non-overlap area fraction on side 1 = 0.00E+00
Non-overlap area fraction on side 2 = 5.00E-01
Domain Interface Name : Domain Interface 5
Non-overlap area fraction on side 1 = 0.00E+00
Non-overlap area fraction on side 2 = 0.00E+00

So am i wrong ? Can i dedine a interface that the side_1 is bigger than the side_2 ?

Tristan January 13, 2010 13:26

Your question is not very clear. For the 3 domain interfaces you listed: the first is a near perfect overlap between the two surfaces since the non-overlap fractions are very small, in the second the surface associated with side 2 is twice as large as the surface associated with side 1, and in the third the two surfaces overlap exactly. To get an interface where side 1 is larger than side 2, just switch the surfaces associated with the two sides in the definition of Domain Interface 6.

Tristan

feixiangniao January 14, 2010 08:05

Quote:

Originally Posted by Tristan (Post 242454)
Your question is not very clear. For the 3 domain interfaces you listed: the first is a near perfect overlap between the two surfaces since the non-overlap fractions are very small, in the second the surface associated with side 2 is twice as large as the surface associated with side 1, and in the third the two surfaces overlap exactly. To get an interface where side 1 is larger than side 2, just switch the surfaces associated with the two sides in the definition of Domain Interface 6.

Tristan


:) Thank you very much.
My question is that can i define the interface where the side_1 is larger than the side_2. Can the cfx trim it automaticly? Can the cfx automatic define or trim the interface so that it is the overlap fractions .
For example , there are two surfaces where the side_1 is larger than the side_2. I want to analyze the heat-transfer in the two body. SO, can i directly define a interface where the surfaces touches , without caring about whether they fully overlap ?

Tristan January 14, 2010 13:13

You can define an interface where the two surfaces do not match exactly but you need to set the appropriate non-overlap boundary conditions to tell CFX what to do in the region where they don't overlap.

Tristan

feixiangniao January 14, 2010 20:51

Quote:

Originally Posted by Tristan (Post 242638)
You can define an interface where the two surfaces do not match exactly but you need to set the appropriate non-overlap boundary conditions to tell CFX what to do in the region where they don't overlap.

Tristan

:) Thank you very much.


All times are GMT -4. The time now is 12:10.