Revision as of 16:13, 9 June 2024 edit Josve05a (talk \| contribs) Autopatrolled, Extended confirmed users, New page reviewers, Pending changes reviewers, Rollbackers 157,551 edits →Size: \| Add: isbn, date, title, doi, authors 1-3. Upgrade ISBN10 to 13. \| Use this tool. Report bugs. \| #UCB_Gadget ← Previous edit		Revision as of 00:05, 10 June 2024 edit undo Josve05a (talk \| contribs) Autopatrolled, Extended confirmed users, New page reviewers, Pending changes reviewers, Rollbackers 157,551 edits m →Tip clearance with backbone bending and case out-of-roundness: \| Altered template type. Add: pages, issue, volume, journal, date, title, doi, authors 1-1. Changed bare reference to CS1/2. \| Use this tool. Report bugs. \| #UCB_Gadget Next edit →
Line 299: <gallery widths="200px" heights="150px" mode=packed class="center"> File:American Airlines C.R. Smith Museum May 2019 17 (Pratt & Whitney JT3D).jpg\|The [[Pratt & Whitney JT3D]] is an example of an early turbofan engine. These engines typically encountered bending along the length of the engine and localised out of roundness where the thrust was transferred from the engine. These issues caused no real concern because thrust levels which caused the distortions were low enough and blade clearances were large enough.<ref>Load distributing Thrust Mount, US patent 3,844,115, column 1 line 66</ref> File:JT9D on 747.JPG\|A [[Pratt & Whitney JT9D]] museum exhibit with none of the accessories, tubes, wiring and cowls which cover a functional engine. Revealed are the casings bolted together which make up the structural backbone of the engine.<ref>{{cite journal \| url=https://doi.org/10.1115/1.2011-MAR-6, '\| doi=10.1115/1.2011-MAR-6 \| title=Mounting Troubles' \| date=2011 \| last1=Langston \| first1=Lee S. \| journal=Mechanical Engineering \| volume=133 \| issue=3 \| pages=46–49 }}</ref> The engine thrust is transferred to the aircraft pylon at the top of the turbine case. As this is above the engine centerline where the thrust acts it causes backbone bending in the core engine<ref>https://ntrs.nasa.gov/citations/19790022018, "Energy Efficient Engine Flight Propulsion System",'Mounting System' 4.11.2.3</ref> which in turn causes causes blade tip rubs and performance loss. File:2016.10.13.111932 Detail GE90 jet engine Future of Flight Center & Boeing Tour Everett Washington.jpg\|[[General Electric GE90]] shows one of two locations (45 degrees either side of top centre) on fan frame where engine thrust is transferred by links to the rear thrust mount for transfer to the aircraft pylon.<ref name="patent" /> File:GE90-115B.jpg\|GE90 shows one of two thrust links to the rear thrust mount on the exhaust case. Early JT9D and CF6 engines had thrust transferred from a single ___location on the top of the engine backbone which distorted the casing requiring increased tip clearances to prevent rubs. Acceptable distortion, with smaller tip clearances, was obtained if thrust was shared between 2 locations, one either side of vertical. This is common on modern engines of this type.

Jet engine performance: Difference between revisions