[Paulie]

Hi,
I want to simulate a cooling of flowing water inside few parallel tubes and air flows around the two tubes. The mesh is huge and to spare some elements I want connect the 1st tube outlet to the 2nd tube inlet and the 2nd tube outlet to 3rd tube inlet... etc. The ends of the tubes are not adjacent. They lay in one plane but in some distance from each other. Is there a possibility to use correctly an interface boundary or an UDF is necessary? If the usage of an interface is possible please give me a tip how to set it for this case.
Thank you in forward for the help.
P.
PS: I'm sorry for the wrong title, it should be "non adjacent interfaces". I suppose, I can´t change it additionally?