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January 13, 2010, 08:34 
GGI (General Grid Interface) Connections

#1 
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liuhuan
Join Date: Dec 2009
Posts: 13
Rep Power: 8 
hello,everyone.
In the helpdocument of GGI (General Grid Interface) Connections, GGI connections permit nonmatching of node location, element type, surface extent, surface shape and even nonmatching 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 solidsolid 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 Nonoverlap area fraction on side 1 = 7.21E05 Nonoverlap area fraction on side 2 = 6.44E08 Domain Interface Name : Domain Interface 6 Nonoverlap area fraction on side 1 = 0.00E+00 Nonoverlap area fraction on side 2 = 5.00E01 Domain Interface Name : Domain Interface 5 Nonoverlap area fraction on side 1 = 0.00E+00 Nonoverlap 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 ? 

January 13, 2010, 13:26 

#2 
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Tristan Burton
Join Date: Mar 2009
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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 nonoverlap 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 

January 14, 2010, 08:05 

#3  
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liuhuan
Join Date: Dec 2009
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Quote:
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 heattransfer in the two body. SO, can i directly define a interface where the surfaces touches , without caring about whether they fully overlap ? 

January 14, 2010, 13:13 

#4 
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Tristan Burton
Join Date: Mar 2009
Posts: 43
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You can define an interface where the two surfaces do not match exactly but you need to set the appropriate nonoverlap boundary conditions to tell CFX what to do in the region where they don't overlap.
Tristan 

January 14, 2010, 20:51 

#5 
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liuhuan
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