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The Rolls-Royce RB.41 Nene is a 1940s British centrifugal compressor turbojet engine. The Nene was essentially an enlarged version of the Rolls-Royce Derwent with the minimal changes needed to deliver 5,000 lbf, making it the most powerful engine of its era. The Nene 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.〔 It was named after the River Nene (and not the Hawaiian goose with the same name) in keeping with the company's tradition of naming its jet engines after rivers. The design saw relatively little use in British aircraft designs, being passed over in favour of the axial-flow Avon that followed it. Its only widespread use in the UK was in the Hawker Sea Hawk and the Supermarine Attacker. In the US it was built under licence as the Pratt & Whitney J42, and it powered the Grumman F9F Panther. Its most widespread use was in the form of the Klimov RD-45, which powered the famous Mikoyan-Gurevich MiG-15. A more powerful slightly enlarged version of the Nene was produced as the Rolls-Royce Tay. ==Design and development== The Nene was designed and built as a result of an early 1944 Air Ministry request for an engine of 4,200 lb thrust, and an engine was schemed-out by Stanley Hooker and Adrian Lombard as the B.40. In the summer of 1944 Hooker visited the USA and discovered that General Electric already had two engine types of 4,000 lb thrust running. On returning to the UK Hooker decided to go for 5,000 lb of thrust, and working with Lombard the B.40 was transformed into the B.41, later to be called the Nene. Based on the B.40, the impeller was enlarged to 28.8 inches to handle an airflow of 80 lb/sec, while the overall diameter of the engine was reduced to 49.5 inches. Other features were incorporated from Derwent testing, with a Type 16 compressor casing, and nine individual combustion chambers developed by Lucas, and the resulting B.41 prototype was built within six weeks, and was ready for its first run on 27 October 1944. A number of snags delayed the run until nearly midnight, when with almost the entire day and night shift staff watching, an attempt was made to start the engine, without the inlet vanes, which had not yet been fitted. To everyone's dismay the engine refused to light - positioning the lighter was a trial-and-error affair at the time. On the next attempt, Denis Drew unscrewed the igniter and as the engine ran up to speed, lit the engine with an oxy-acetylene torch. The engine was run up to 4,000 lb and more, and a cheer went up around the assembled personnel. Upon Hooker's arrival next morning, and informed that the inlet vanes had been fitted during the night, Hooker was satisfied to see the thrust gauge needle registering 5,000 lb, making the B.41 the most powerful jet engine in the world. Weight was around 1,600 lb〔"World Encyclopedia of Aero Engines - 5th edition" by Bill Gunston, Sutton Publishing, 2006, p.193〕 Although based on the "straight-through" version of the basic Whittle-style layout, the Nene used a double-sided centrifugal compressor for improved pressure 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. Early airborne tests of the Nene were undertaken in an Avro Lancastrian operated by Rolls-Royce from their Hucknall airfield. The two outboard Rolls-Royce Merlins were replaced by the jet engine. The Nene's first flight however was in a modified Lockheed XP-80 Shooting Star.〔http://www.flightglobal.com/pdfarchive/view/1946/1946%20-%200764.html〕 After seeing the Nene running, at an after work drink at the Swan & Royal Hotel, Clitheroe, and hearing the complaints about a lack of any official application for the engine, someone - thought to be Whittle - suggested that the Nene be scaled-down to fit a Meteor nacelle. J.P. Herriot or Lombard did the calculation on a tablecloth and announced a thrust of 3,650 lb. At this time they were attempting to increase the Derwent's thrust from 2,200 lb to 2,450 lb, and the idea seemed "too good to be true". On hearing this, Hooker did a quick calculation and announced, "We've got a 600-mph Meteor".〔"World Encyclopedia of Aero Engines - 5th edition" by Bill Gunston, Sutton Publishing, 2006, p.194〕 Drawings for the 0.855 scale Nene, now known as the Derwent V, were started on 1 January 1945 and on 7 June the engine began a 100-hour test at 2,600 lb, soon reaching 3,500 lb. Weight was 1,250 lb. By 1946 thrust had been increased to 4,200 lb using Nimonic 90 turbine blades.〔 The development of the Nene was continued with this scaled-down version, the Derwent V having no direct relationship to the earlier Derwent series. On 7 November 1945, the first official air speed record by a jet aircraft was set by a Meteor F.3 of 606 miles per hour (975 km/h) powered by the scaled-down Nene, the Derwent V 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Rolls-Royce Nene」の詳細全文を読む スポンサード リンク
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