Coupled wall for Interface/External Flow pass through internal flow
 

Hi,

I run across problem that is external flow get through/pass through tubes(internal flow)

Someone advise me not to be neccessary to specify coupled wall in interface.

But external flow get through internal flow(tubes)

Someone can help me what should I do?

I think that coupled wall separate both internal and external flow

https://imageshack.com/i/p8ErVyMZp

and there is no flow in upper right in system.Are there any informations about it?

Kind Regards,