Rolls-Royce Nene

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The Rolls-Royce Nene was a 1940s British centrifugal compressor turbojet engine.

[edit] Development

The Nene or RB.41, was Rolls-Royce's third jet engine to enter production, designed and built in an astonishingly short five-month period in 1944, first running on 27 October 1944. The design saw little use in British designs, being passed over in favour of the Avon that followed it. Its only widespread use in Great Britain was in the Hawker Sea Hawk and the Supermarine Attacker. Pratt and Whitney took out a licence on the Nene and it went on to power many early carrier-based aircraft, notably the Grumman F9F Panther, as the Pratt & Whitney J42. Twenty-five were given to the Soviet Union as a gesture of goodwill, and were reverse engineered to develop the Klimov RD-45, and a larger version, the Klimov VK-1, which soon appeared in various Soviet fighters including Mikoyan-Gurevich MiG-15. It was briefly made under licence in Australia for fitment to the RAAF De Havilland Vampire fighters.

Although based on the "straight-through" version of the basic Whittle-style layout, the Nene used a double-sided centrifugal compressor for improved compression ratio and thus higher thrust. It was during the design of the Nene that Rolls decided to give their engines numbers as well as names, with the Welland and Derwent keeping their original Rover models, B/23 and B/26. It was later decided that these model numbers looked too much like those for bombers, and "R" was added to the front, the "R" signifying "Rolls" and the original Rover "B" signifying Barnoldswick. This RB designation scheme continues to this day.

The Nene doubled the thrust of the earlier generation engines, with early versions providing about 5,000 lbf (22.2 kN), but remained generally similar in most ways. This should have suggested that it would be widely used in various designs, but the Gloster Meteor proved so successful that the Air Ministry felt there was no pressing need to improve upon it. Instead a series of much more capable designs using the Rolls-Royce Avon were studied, and the Nene generally languished.

The Nene was used to power the first civil jet aircraft, a modified Vickers Viking, which flew first on 6 April 1948.

[edit] Specifications (Nene)

General characteristics

• Type: Turbojet
• Length: 97 in (2,464 mm)
• Diameter: 49.5 in (1,257 mm)
• Dry weight: 726 kilograms (1600 pounds)

Components

• Compressor: Dual-entry centrifugal compressor with two-sided impeller
• Combustors: 9 flow-combustion chambers
• Turbine: Single-stage axial flow
• Fuel type: Aviation kerosene with 1% lubricating oil

Performance

• Thrust: 5,000 lbf (22.2 kN) at 12,400 rpm for takeoff
• Thrust-to-weight ratio: :1

[edit] References

• Bridgman, L, (ed.) (1998) Jane's fighting aircraft of World War II. Crescent. ISBN 0-517-67964-7
• The Nanton Lancaster Society