Mixed stairstep + submap meshing trouble

Paweł

Hello Guys. I'm preparing power boiler model in gambit. To size the mesh over the burners i have divided my volume into parts (smaller one). At the volume with contains burners (velocity-inlet faces), I am using stairstep meshing scheme, which creates virtual volume. After importing mesh to Fluent, virtual areas doesn't seem to be in the same zone (but they should), as the rest of the model. Fluent sees virtual volumes as a different objects, and creates wall boundary at the contact face of virtual and real volume. Do you how to solve this problem? I mean what boundary conditions give on the contact faces, or how to force stairstep mesh to not create virtual volume.

The model is available at: http://194.146.255.19 (see JPG files, or dbs)

Thanks for your help and time, Paweł (Poland)