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Aviation History
1983
1983 - 0390.PDF
PROPULSION More jobs cutsatR-R and P&W Job losses from aero-engine manufacturers on both sides of the Atlantic continue as the recession in the airline indus try continues to bite. Pratt & Whitney has announced that it intends to reduce its East Hartford workforce by nearly 10 per cent, while Rolls-Royce is to lose 2,000 jobs this year as part of its plan to reduce the Derby workforce by 5,100. Both companies' pruning is being managed entirely through voluntary redun dancies and early retirement. Declining demand for new aircraft is blamed, although improvements in efficiency owing to the introduction of advanced manufacturing technology is also a cause. Pratt & Whitney reports reductions in both commer cial and military business, particularly in declining orders for spare parts. The company expects engine ship ments this year to be about 18 per cent below the 1982 level. The latest round of job cuts will leave it with a workforce of 28,000. Rolls-Royce is reducing its total workforce by 12,000 over two years, to just below 44,000. R-R opens new testbed BRISTOL Engine core testing moves into a new era at Rolls-Royce with the entry into service this month of a £2 million sea- level testbed. Located at its Bristol test site, the facility will be able to test cores for all types of engine with a computer enabling up to 500 different parameters to be measured at once. A new "Super X-ray" machine developed by scientists at the Harwell atomic energy establishment and at Bristol's advanced projects department allows actual clearances within the core to be seen while it is running. Another feature is that airflow into the core can be accurately simulated. .584 Aft fan inlet Front fan Front fan vectoring nozzle Vought looks at V/Stol workhorse DALLAS Vought, the company pushing the tandem-fan propulsion system for supersonic V/Stol fighters, has come up with an interesting design (above) of a Mach 0-8 tandem-fanned V/Stol utility aircraft for the US Navy. The company thinks that the proposed aircraft would suit the Navy's Type A requirement for a multi-role subsonic transport. Tandem fan is the answer, says Vought, to the tough requirements placed on V/Stol engine inlets. For the subsonic application seen here, the parallel-flow version of the engine is chosen, in which airflow through front and rear fans is kept separate (right). In the series flow supersonic version, the airflow is only separated for vertical take-off. For forward flight—the front fan "supercharges" the air before it enters the rear fan and core. Both nacelles are struc turally integrated with the fuselage in Vought's design. Each contains its own propulsion system, consisting of a core engine, two fixed- pitch fans with variable inlet guide-vanes, and associated inlets and nozzles. The fans are co-axial and the shaft join ing them passes through a combiner gearbox driving a cross-shaft for one-engined operation. During conventional flight, the flows are vectored aft. For V/Stol, the front and rear nozzles move downwards to produce a "four-poster" efflux pattern for landing and take off. The top inlet has been arranged to benefit from the favourable flow field of the front inlet. Both inlets have large radii for good performance during take-off and transition. The forward nozzle is two- dimensional, a simple two- piece deflector being used to vector thrust. At the rear, core and fan airflow is mixed before being vectored. Nasa, which has been reviewing "Type A" designs from several manufacturers, says that funding is currently very limited, and that many of the requirements could be satisfied by a tilt-rotor type of machine, such as the JVX. But tandem fan, it says "is not on the backburner yet". Soviets studying propfan A Russian "propfan" is on the Antonov design bureau draw ing boards, according to the magazine Skrzydlata Polska. On its back page, the journal depicts a 1:6 scale model of an eight-bladed airscrew for engines in the 2,000-3,000 s.h.p. range. Another project is appar ently the development of a multi-bladed propeller to handle 3,000-5,000 s.h.p. The magazine says that on short/medium-length sectors the fuel consumption could be 20 per cent less than that of a jet engine. This is about the same as the figure mentioned by Hamilton Standard for the propfan it is developing with Nasa. Funding in the USA for advanced propellers has recently suffered a setback, so the Soviet version may see action first. France is also in the early stages of propfan development.
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