The Rolls-Royce/SNECMA M45H is an Anglo-French medium

bypass ratio The bypass ratio (BPR) of a turbofan engine is the ratio between the mass flow rate of the bypass stream to the mass flow rate entering the core. A 10:1 bypass ratio, for example, means that 10 kg of air passes through the bypass duct for ev ...

turbofan produced specifically for the twin-engined

VFW-Fokker 614 The VFW-Fokker 614 (also VFW 614) was a twin-engined jetliner designed and constructed by West German aviation company VFW-Fokker. It is the first jet-powered passenger liner to be developed and produced in West Germany (the East German Baade 152 ...

aircraft in the early 1970s. The design was started as a collaborative effort between

Bristol Siddeley Bristol Siddeley Engines Ltd (BSEL) was a British aero engine manufacturer. The company was formed in 1959 by a merger of Bristol Aero-Engines Limited and Armstrong Siddeley Motors Limited. In 1961 the company was expanded by the purchase of t ...

and

SNECMA Safran Aircraft Engines, previously Snecma (''Société nationale d'études et de construction de moteurs d'aviation'') or Snecma Moteurs, is a French aerospace engine manufacturer headquartered in Courcouronnes and a subsidiary of Safran. It ...

Design and development

The VFW 614 was designed to operate over short sectors with up to a dozen flights a day. The engines were optimized for 30-minute sectors at a cruise altitude of 21,000 feet at Mach 0.65. Only a few minutes would be spent at the cruise rating and most of the flight would be at the higher climb rating or at a descent setting. The engine had a low turbine entry temperature and comparatively low rotational speed. The engine was designed to be uprated without drastic redesign. Three options were water injection (+10% thrust), improved HP turbine (+10% thrust), addition of a zero-stage to the LP compressor (+25% thrust). The M45H-01 was to have a

thrust-specific fuel consumption Thrust-specific fuel consumption (TSFC) is the fuel efficiency of an engine design with respect to thrust output. TSFC may also be thought of as fuel consumption (grams/second) per unit of thrust (newtons, or N), hence ''thrust-specific''. This fi ...

(TSFC) of . The engine was developed at the time of the Rolls-Royce bankruptcy which resulted in delays in developing the engine.Swanborough 1971, p.371.

Variants

;M45F: Civil low bypass turbofan for take-off. ;M45G: Military low bypass turbofan for take-off, wet. ;M45H:Civil medium bypass turbofan for take-off, wet. ;RB.410:Rolls-Royce designation for the M45SD-02 geared turbofan ;M45SD-02:

Engines on display

Rolls-Royce/SNECMA M45H engines are on display as part of the aero engine collection at the

Royal Air Force Museum Cosford The Royal Air Force Museum Cosford, located in Cosford in Shropshire, is a free (currently, 2022) museum dedicated to the history of aviation and the Royal Air Force in particular. The museum is part of the Royal Air Force Museum, a non-departme ...

and the

Musée aéronautique et spatial Safran The Musée aéronautique et spatial Safran ( en, Aeronautics and Space Museum Safran, italic=yes) is a French private aviation museum located in Melun, Seine-et-Marne. Established in May 1989 the museum contains a large collection of historic and ...

. Additionally, an engine, with its cowl and pylon, is displayed at the

Deutsches Museum Flugwerft Schleissheim Flugwerft Schleissheim is an aviation museum located in the German town of Oberschleißheim near Munich, it forms part of the Deutsches Museum collection and complements the aviation exhibits on display at the main site. The museum was opened on ...

; this museum also displays a VFW-614, which has two engines mounted.

Specifications (M45H Mk.501)

References

External links

Stol Fans from Dowty
a 1971-01-21 ''Flight International'' article {{DEFAULTSORT:Rolls-Royce SNECMA M45H Medium-bypass turbofan engines 1970s turbofan engines M45H