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Author Topic: Rolls-Royce RB Designations  (Read 8731 times)

Offline Apophenia

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Re: Rolls-Royce RB Designations
« Reply #15 on: August 21, 2016, 01:57:51 pm »
Cheers Hood! Notes on those typos have now been added.

Offline CJGibson

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Re: Rolls-Royce RB Designations
« Reply #16 on: September 07, 2016, 04:24:34 am »
Content to date collated and put on a pdf.

Chris

Offline Hobbes

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Re: Rolls-Royce RB Designations
« Reply #17 on: January 26, 2019, 06:06:07 am »
Quote
RB.178 - [Project] 1961 'Super Conway', high-bypass Medway devel.
 - RB.178: Led to development of third generation RB.203 Trent
 -- Orig. intended as SST engine, B747 1st subsonic application
 -- HBN 100 'Airbus' (x 2), B747* and SC.5/41 Jet Belfast (x 4)
 -- https://www.flightglobal.com/pdfarchive/view/1964/1964%20-%202365.html
 - RB.178-16: July 1966 2-shaft trials engine
 - RB-178-51: First 3-spool version, 44,000 lbf,* abandoned
 -- * Gunston has proposed rating as 45,000 lbf (reply #2)
 - RB-178-61: 2-spool test engine, 27,500 lbf
 -- https://www.flightglobal.com/FlightPDFArchive/1967/1967%20-%200028.PDF
 - RB.178 demonstrator program terminated in 1966
 -- * Proposed RB.178 joint production with General Electric
 -- http://www.secretprojects.co.uk/forum/index.php?topic=12702.0


I think RB.178-61 is a typo, the trials engine was the -16

Engine dimensions:
Demo engine RB.178-61, Two-spool version, bypass 2.75:1, diameter 62.5" = 1.58 m (from Flight 1967 - 0028), 27.5 klbf

From Aviation Magazine International - Numéro 448 - 1-8-1966:
 - demo engine 11566 kgf = 113.4 kN = 25.4 klbf
 - Two-spool version with bypass ratio 4:1: length 3.35 m diameter 2.5 m, thrust 11500-13500 kgf =  112.7-132.4 kN = 25.3-29.7 klbf
 - Three-spool version (as proposed for Boeing 747) diameter 3.35 m, thrust 20000-23000 kgf  = 196-225 kN = 44-50.7 klbf


From 'Transatlantic Betrayal, the RB.211 and demise of Rolls Royce ltd', page 92:
 - RB.178-14 was a two-spool demonstrator, 27 klb, bypass ratio 2.3:1, 25% lower specific fuel consumption than predecessors.
 - RB.178-16 intended for VC-10 DB.265 Superb
after cancellation of Superb in 1966, RR's Lombard ordered the RB.178 to be scaled up to get it accepted as a Boeing 747 engine

1966-1399 Flight: RB.178-51 at 44klb designed for Boeing 747 and unidentified Airbus. Bypass ratio 6:1, dry weight 7724 lb.

so plenty of disagreement between sources. I asked RR Heritage Trust for information on RB.178, but didn't get an answer. I've built 2 models (Jet Belfast and VC-10 Superb) with RB.178 using the 1.58 m diameter figure...


Offline Apophenia

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Re: Rolls-Royce RB Designations
« Reply #18 on: January 29, 2019, 02:06:46 pm »
'RB.178-61' being a typo does make sense Hobbes. That would explain why a lower-power twin-spool engine 'follows' the higher-powered triple-spool RB.178-51!