N79969 From , joined Dec 1969, posts, RR: Posted (11 years 10 months 1 week 19 hours ago) and read 3792 times:
Does anyone know the purpose of the nozzles at the end of CF6 engines on MD-11? They don't appear on PW powered MD-11 nor do they appear on CF6-powered 747 or 767. They reappear on the A300/310/330 that are powered by CF6.
Also they appear on all engines available on the 777. I have wondered what determines when these exhaust nozzles are used or whether they inside the cowling or actually stick out.
LMP737 From , joined Dec 1969, posts, RR:
Reply 7, posted (11 years 10 months 6 days 3 hours ago) and read 3671 times:
The nozzle you are reffering to is known as the exhaust plug. It's purpose is to form a convergent-divergent duct along with the exhasut nozzle to aid in the production of thrust.
THe PW 4460 on the MD-11 does have an exhaust plug, you just can't see it from the ground. The same goes for CF6 powered 747 and 767's. Other engines such as the RB-211 and V2500 fall into this category also.