[SerSe]

Dear sir,

I have a simple problem to simulate, i.e., a convergent air nozzle inserted at the centerline of a circular exhaust gas pipe. Geometry is axisymmetric, I am modelling only half section. The nozzle ejects air at sonic velocity, and has to push forward the exhaust gas while mixing to it.
In order to have mapped mesh with increasing size from walls for boundary layer capturing, I have inserted a line which represents the exit of the nozzle and divided it in certain number of elements. By the way, I am obliged to assign this edge a boundary condition, otherwise Fluent treats it as wall. I am using a pressure outlet BC... Is this way correct? (I get reverse flow warnings in Fluent during simulation...)
Is there any way to use construction edges to obtain nice geometry/mesh and then delete them without any adverse effect? Should I use blocking features?

Thanks for your help.

Regards,

SerSe