Keta From Germany, joined Mar 2005, 449 posts, RR: 0 Posted (10 years 11 months 2 weeks 3 days 13 hours ago) and read 9936 times:
The jet engine inlet is a crucial part for engine efficiency. It must be well designed so the air flows correctly into the engine. So, I'd say that the engine manufacturer does this job. But doesn't the nacelle modify the airflow around the wing? I guess that the aircraft designer has to take this into account. I too remember Airbus saying that one of the advantages introduced in the A380 was the efficient design of the nacelles (I think based in the A346 work). So, who designs the nacelles?
Broke From United States of America, joined Apr 2002, 1325 posts, RR: 3
Reply 1, posted (10 years 11 months 2 weeks 3 days 11 hours ago) and read 9918 times:
My experience is in older airplanes. On the DC-8, the nacelles were designed by either Douglas, the engine manufacturer, or the STC holder.
For instance; on the DC-8-50 series and the DC-8-61 the nacelle was designed by P&WA. On the DC-8-62 and DC-8-63, the nacelle is a Douglas design.
On the DC-8-70 series, the nacelle was designed by Camacorp which was the company that developed the STC changing the -60's to -70's.
It all depends on the circumstances and how much risk and design sharing is contacted when developing an airplane.
AeroWeanie From United States of America, joined Dec 2004, 1612 posts, RR: 51
Reply 2, posted (10 years 11 months 2 weeks 3 days 7 hours ago) and read 9853 times:
Boeing designed the first JT9D nacelles and the responsibility was split between the aero group (everything outside the stagnation point) and the propulsion group (everything inside the stagnation point). I believe that GE and RR have always designed their own nacelles. P&W started to design their own nacelles in the early 1980s.
PlainSmart From , joined Dec 1969, posts, RR:
Reply 3, posted (10 years 11 months 2 weeks 3 days 5 hours ago) and read 9818 times:
Generally today most manufactures of engines design inlets because they spend a lot of time and money engineering how the air will flow through the engine. For military applications this is especially true for supersonic jets to control the shocks and velocities of the air hitting the compressor.
727EMflyer From United States of America, joined Mar 2005, 547 posts, RR: 0
Reply 4, posted (10 years 11 months 2 weeks 3 days 5 hours ago) and read 9813 times:
Evidence of the engine manufacturer designing the nacelles can be seen by looking at a RR example. Look at the similarity of nacelle design among RR and IAE (PW, RR, and others) installations on these four aircraft from three different manufacturers: Boeing 744, 752; McDonnel Douglas MD-90; and Airbus A320
The similarity is lesser on the MD-90, and there isn't an alternate manufacturer to compare against but I think you can still see the influence.
Another thing to think about with nacelles is that they affect how the bypass air mixes with the exhaust from the core. With the evolution of turbofan's you can see how the nacelles duct the bypass air further along the length of the engine. You can see a good example by looking at early design PW4000's used on 767 vs. the more recent 4000's built for 777's
Lightsaber From United States of America, joined Jan 2005, 15638 posts, RR: 100
Reply 8, posted (10 years 11 months 2 weeks 2 days 16 hours ago) and read 9680 times:
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Quoting AeroWeanie (Reply 2): P&W started to design their own nacelles in the early 1980s.
Pratt designed the Nacelle on the A330 and due to the potential profit would like to design more nacelles. The pw4000 94" (4056/4062/4262, etc.) actually use the same nacelle as the GE CF-6!
Many nacelles are designed by BF Goodrich. Just like engines, nacelle manufacturers compete for the design win.
Does anyone know the 787 nacelle vendor? With GE and RR sharing a nacelle... its going to be a cat fight to have it optimized for each engine.
Quoting 727EMflyer (Reply 4): Evidence of the engine manufacturer designing the nacelles can be seen by looking at a RR example.
RR likes to mix the fan and turbine air to quiet the engine. This philosophy was extended to the V2500. If you look at the pw6000 nacelle, you'll see that all mixing nacelles look very similar from the external perspective. Alas, I don't know who designs the nacelles for RR (or if they do their own).
"They did not know it was impossible, so they did it!" - Mark Twain
WhiteHatter From , joined Dec 1969, posts, RR:
Reply 9, posted (10 years 11 months 2 weeks 2 days 14 hours ago) and read 9664 times:
Quoting Lightsaber (Reply 8): RR likes to mix the fan and turbine air to quiet the engine. This philosophy was extended to the V2500. If you look at the pw6000 nacelle, you'll see that all mixing nacelles look very similar from the external perspective. Alas, I don't know who designs the nacelles for RR (or if they do their own).
However they have gone back to a more conventional design on the Trent 500, 800, 900 and 1000.
Jeb94 From United States of America, joined Oct 2004, 663 posts, RR: 4
Reply 11, posted (10 years 11 months 1 week 4 days 15 hours ago) and read 9445 times:
For most jet aircraft, the nose cowl, cowl doors, and thrust reverser are all rovided by the airframe manufacturer. They may very well have been designed by another company for specific applications but it is the airframe manufacturer that provides them on the aircraft. P&W, GE, RR, Williams, etc just build the engines.
Liedetectors From United States of America, joined Jul 2005, 360 posts, RR: 0
Reply 14, posted (10 years 4 months 1 week 1 day 21 hours ago) and read 8786 times:
Quoting Jeb94 (Reply 11): For most jet aircraft, the nose cowl, cowl doors, and thrust reverser are all rovided by the airframe manufacturer.
Not true. The cowl and the nozzle (and TRU in the case of a bucket setup) are designed by the engine manufacture with input from the airframe manufacturer. The thrust reverser is contracted out and the engine manufacter will coordinate with them. Think about it, inorder for an engine to work properly, the size of the inlet area and nozzle are crutial for proper operation of the engine. Therefore the engine maker must have control over it.
The design of the nacelle is done by both the engine manufacter and the airframe manufacter. The airframe manufacturer will define how many accessories must be hooked to the engine. ie gearboxed, FADECs etc. On some engines you may notice a buldges or asymetries in the nacelle. This is where the gearboxes and such are.
On a side note, the pylon is sized by the ECS system maker as they must size the ducts to handle the bleed offtake from the engine. Sometimes the preecoolers are found here. The aerodynamics group at the airframe maker will then design an airfoil shaped fairing around the engine mounts and bleed ducts.
Lehpron From United States of America, joined Jul 2001, 7028 posts, RR: 20
Reply 15, posted (10 years 4 months 4 days 18 hours ago) and read 8648 times:
Question about the tail cone behind the turbine: Does it act as an aerospike ramp, providing a bit of thrust by expanding any jet exhaust pressure? Or is the thrust pressure fully expanded aft of the turbine? Or is the turbine cone something for higher altitude pressure efficiency than ground level?
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