N79969 From , joined Dec 1969, posts, RR: Posted (13 years 6 months 3 weeks 4 days 8 hours ago) and read 5602 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 United States of America, joined May 2002, 4891 posts, RR: 21
Reply 7, posted (13 years 6 months 3 weeks 2 days 15 hours ago) and read 5481 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.