TinPusher007 From United States of America, joined Feb 2005, 1008 posts, RR: 1
Reply 1, posted (9 years 2 months 1 day 11 hours ago) and read 21131 times:
I believe the one on the Trent powered A330's are called 'target type' or 'bucket type' reversers. I've heard both terms for this type. They open similarly to the calmshell type, but like the translating cowl type, they only reverse the fan air.
"Flying isn't inherently dangerous...but very unforgiving of carelessness, incapacity or neglect."
Crownvic From United States of America, joined Oct 2004, 2128 posts, RR: 5
Reply 3, posted (9 years 2 months 1 day 8 hours ago) and read 21079 times:
Although the function is similar to the translating cowl, you forgot to mention the "Cascade" type. This is what is on the later 727's (not re-engined) and many other early generation airliners (BAC-111, Trident, TU-134, TU-154B2, DC-8-50/61).
FriendlySkies From United States of America, joined Aug 2004, 4131 posts, RR: 5
Reply 5, posted (9 years 2 months 1 day 7 hours ago) and read 21050 times:
Quoting Crownvic (Reply 3): Although the function is similar to the translating cowl, you forgot to mention the "Cascade" type. This is what is on the later 727's (not re-engined) and many other early generation airliners (BAC-111, Trident, TU-134, TU-154B2, DC-8-50/61).
I believe Avon-powered Caravelles with reversers also featured this type.
Jetlife2 From United States of America, joined Jul 2006, 221 posts, RR: 24
Reply 7, posted (9 years 2 months 10 hours ago) and read 20914 times:
The third type are called "blocker doors".
This can get confusing because there are some engines which use a combination of translating cowl plus blocker doors, in which case the blocker doors are a subassembly not the only element. See here for more detail
F14D4ever From United States of America, joined May 2005, 319 posts, RR: 4
Reply 8, posted (9 years 2 months 10 hours ago) and read 20905 times:
Quoting Jetlife2 (Reply 7): there are some engines which use a combination of translating cowl plus blocker doors, in which case the blocker doors are a subassembly not the only element
The translation of the cowl only exposes the cascade. It does not by itself divert air through the cascade. The blocker doors are the requisite pieces which accomplish the diversion of airflow through the cascade, thereby producing reverse thrust.
So a so-called 'cascade' reverser consists of both the namesake cascade and the blocker doors.
This type of reverser is used with the CF34-8, CF34-10, CF6, and CFM56, among others.
Careful now, lest the bogeyman come calling... Cascade reversers use blocker doors as well.
For the Mech types, do petal reversers block the bypass all the way around? It seems like they'd need to or else a sizeable amount of bypass air would still go out the back.
But, if they do, how do they ensure that all the blocked air goes out the open petals? Since (unlike cascade systems) the open petals are small in relation to the intake, it seems like you'd get some air going back out through the fan.
Curious the amount of interest folks have in thrust reversers... Must be the mechanicals and such, like with landing gear.
Yikes! From Canada, joined exactly 14 years ago today! , 284 posts, RR: 1
Reply 12, posted (9 years 1 month 3 weeks 6 days 10 hours ago) and read 20736 times:
Missed in the above:
The cascade/sleeve/petal/other types of reversers deflect only high-bypass flow. Core flow continues in the traditional vector. But core thrust on high-bypass engines during landing roll contribute to only about 25% of total engine thrust.
Clamshell type reversers re-direct the total flow of low-bypass engines, are very noisy and are high-maintenance.
High-energy reverse thrust is most effective at high forward speeds. Reverse thrust does not reduce landing roll if used in conjunction with autobrakes. Reverse thrust does reduces brake wear.
Whereas brakes are cheaper to replace than engine parts, I tend to use a deceleration strategy that enables me to clear the runway where I want to, usually resulting in a fixed autobrake value and idle reverse.
2H4 From United States of America, joined Oct 2004, 8956 posts, RR: 59
Reply 13, posted (9 years 1 month 3 weeks 6 days 8 hours ago) and read 20732 times:
AIRLINERS.NET CREW DATABASE EDITOR
I just wanted to point out just how professional this forum is. The original poster's question is asked and addressed fairly regularly, but rather than scold the new member for not using the search function, a polite and interesting discussion resulted.
Welcome to Tech/Ops, YULspotter....you'll love it here!