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ROLLS-ROYCE SNECMA OLYMPUS
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| 25 July 2000 |
Though private restoration groups are trying to return Vulcan bombers (Olympus 301) to airworthy status, the only Olympus engine currently in operation is the Concorde power plant, the Olympus 593 Mk 610-14-28. This has a convergent/divergent exhaust nozzle, thrust reverser and afterburner system.
Preflight Olympus development engines, designated 593D, were used for bench testing from mid-1964. The first of the Olympus 593 flight-type engines made its initial test run in November 1965. A Vulcan testbed, with a single Olympus 593 mounted beneath its fuselage in a representative Concorde half-nacelle, assisted flight development from September 1966 to July 1977. Concordes have been flying since March 1969.
Production standard Olympus 593 engines powered preproduction and production Concordes. In March 1974, a production standard engine, the Olympus 593 Mk 610, successfully completed an official 150 hour type test. Full certification was achieved in April 1975, when total running time exceeded 40,000 hours.For political reasons only 14 Concordes entered service, seven each for BA and Air France, in 1976.
On 2 March 1999, the 30th anniversary of Concorde flying, an average fleet total of 10 aircraft had flown 920,000 hours. This total included considerably more than 600,000 hours at supersonic speeds, easily exceeding the total supersonic time of all other aircraft in the Western world.
In 1999 the time for the fastest flight NY-London was just under 2 hours 53 min.
The following description refers to the production engine, the 593 Mk 610:
TYPE: Axial-flow, two-spool turbojet with partial afterburning.
INTAKE: Fabricated titanium casing, with zero-swirl five-spoke support for the front LP compressor bearing. In the Concorde, the engine is installed downstream of an intake duct incorporating auxiliary intake and exit door systems and a throat of variable profile and cross-section.
LP COMPRESSOR: Seven-stage axial-flow type, with all blading and discs manufactured from titanium. Single-piece casing machined from a stainless steel forging, electrochemically machined.
HP COMPRESSOR: Seven-stage axial-flow compressor. The first three stages of blades are made from titanium alloy. Remaining stages are made from a heat-resistant material due to very high compressor delivery temperatures during supersonic flight. Steel single-piece casing. Mass flow 186 kg (410 lb)/s. Overall pressure ratio 15.5:1.
INTERMEDIATE CASE: Titanium casing, with vanes supporting LP and HP thrust bearings. Drives for engine-mounted aircraft and engine auxiliary drive gearboxes are taken out through the intermediate casing.
COMBUSTION CHAMBER: Annular cantilever mounted from the rear. Fabricated as single unit from nickel alloy, with all joints butt-welded to ensure reliability. Electrochemically machined. The combustion system burner manifold and the main support trunnions are located around the delivery casing. Total of 16 vaporising burners, each with twin outlets, bolted directly into chamber head. Fuel injectors are simple pipes which enter each vaporiser intake with no physical contact. Combustion leaves virtually no visible smoke in the propulsive jet.
HP TURBINE: Single-stage turbine, with cooled stator and rotor blading.
LP TURBINE: Single-stage, with cooled rotor blades. LP driveshaft coaxial with HP shaft.
JETPIPE: Comprises a straight jetpipe and a pneumatically actuated variable primary convergent nozzle which permits maximum LP-spool speed and turbine-entry temperature to be achieved simultaneously over a wide range of compressor-inlet temperatures. Single-ring afterburner with programmed fuel control as a function of main-engine fuel flow. Monobloc secondary nozzle with each twin nacelle manufactured from Stresskin panels. Each power plant terminates in a pair of `eyelids' which form a variable-area secondary divergent nozzle and thrust reverser. The eyelid position is programmed to maintain optimum power plant efficiency through all the flight regimes: take-off, subsonic cruise and supersonic cruise. When completely closed they act as thrust reversers.
MOUNTING: Main trunnions on horizontal centreline of the delivery casing. Allowance for expansion contained within aircraft pickups. Front stay from roof of the nacelle picks up on the top of the intake casing.
ACCESSORIES: Beneath the compressor intermediate casing are two gearboxes, both mechanically driven off the HP shaft (the LP shaft only has a pulse-probe signal source and provision for hand or mechanical turning). The LH gearbox drives the main engine oil pressure/scavenge pumps and the first-stage fuel pump and fuel control unit. The RH gearbox drives the aircraft hydraulic pumps and integrated-drive generator/alternator.
STARTING: SEMCA air-turbine starter drives the HP spool. Dual high-energy ignition system serves igniters in the annular chamber.
CONTROL SYSTEM: Lucas system, incorporating a mechanically driven first-stage pump and a second-stage pump driven by an air turbine which is shut down at altitude cruise conditions as fuel requirements can be met by the first-stage pump alone. The first-stage pump also supplies afterburner fuel. A fuel-cooled oil cooler is incorporated. An Ultra electronic system - the world's first FADEC in service - with integrated-circuit amplifier, provides combined control of fuel flow and primary nozzle area. Afterburner fuel is controlled by an ELECMA electrical control unit. The fuel system of the production Olympus 593 is substantially lighter than the one previously in use, and it operates at pressures of about one-half those on the earlier system. It also has improved maintenance and installation characteristics. The principal difference is that the piston-type HP pump is replaced by an air turbopump. At altitude cruise conditions, sufficient pressure is available from the first-stage pump alone and the air turbopump is shut down.
FUEL SPECIFICATION: DERD.2494 Issue 7, AIR 3405B (3rd edition, amendment 1), ASTM D-1655-71 (Jet A) and ASTM D-1655-71 (Jet A1).
OIL SYSTEM: Closed system, using oil to specification DERD.2497, MIL-L-9236B. Pressure pump, multiple scavenge pumps and return through Serck fuel/oil heat exchanger.
DIMENSIONS:
| Length (flange to flange) | 4,039 mm (159 in) |
| Length (flange to nozzle) | 7,112 mm (280.0 in) |
| Diameter (inlet) | 1,212 mm (47.75 in) |
WEIGHT, DRY:
| Bare engine | 2,971 kg (6,550 lb) |
| With afterburner, reverser and nozzle | 3,175 kg (7,000 lb) |
PERFORMANCE RATINGS (T-O, S/L, ISA):
| Dry | 139.4 kN (31,350 lb st) |
| Afterburner | 169.2 kN (38,050 lb st) |
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| The full designation of the Concorde engine is Olympus 593 Mk 610 (1996) |
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| Nozzles of the Mk 610 (Type 28), showing one open, the other partly closed for subsonic cruise (1996) |
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| Cutaway drawing of twin-engine Concorde nacelle (1996) |