Grid interfaces in Fluent

Omar Qazi

I am working on a simulation where I want to use a grid that is locally refined at selected points. I planned to carry out the refinement manually by generating the grid in parts and later assembling the grid by defining interfaces. Generally the number of nodes on ether side of an interface are different. I defined coupled interfaces to provide continuity.

The problem I am facing is that the the interfaces seem to be acting as walls in the simulation. The interfaces are generally normal to the incoming flow and the flow diverts at the interface. What am I missing?