Thanks 411A.
So in that case, BPR is only related to the hotstream and any coldstream airflow that is created by the first fan or compressorstage and not the coldstream airflow that the engine might produce outside the engine cowling?
In that case, how do you explain the Ultra High Bypass engine? That is, where do you draw the line between an unducted fan and a propeller?
/LnS
EDIT: I know I'm splitting hairs a bit here, but that is what my students tend to do, so I'd really like to be able to give them a specific and detailed answer.