Rolls-Royce RB.108
| RB.108 | |
|---|---|
| |
| Preserved RB.108 at the Royal Air Force Museum Cosford
| |
| Type | Turbojet |
| Manufacturer | Rolls-Royce Limited |
| First run | 1955 |
| Major applications | Short SC.1 |
| Developed into | Rolls-Royce RB145 lift/cruise engine
|
The Rolls-Royce RB.108 was a British jet engine designed in the mid-1950s by Rolls-Royce specifically for use as a VTOL lift engine. It was also used to provide horizontal thrust in the Short SC.1.
Design and development
The RB.108 was the first direct-lift turbojet produced by Rolls-Royce. It originated from a VTOL concept in which
RB.162, would have a compressor built mainly from glass-fibre composite and have a higher T/W ratio.) The RB.108 bearings and oil
system were designed to operate with an engine attitude envelope which covered engine and aircraft tilting while transitioning between hovering and forward flight. When a fifth engine was installed in the SC.1 to provide forward thrust it had to be mounted at about 45 degrees to remain within the envelope. The exhaust was directed horizontally with a curved jetpipe.
Operational history
The RB.108 was used in the
SG 1262
used five RB.108s, three mounted in tandem on the centreline, with one RB.108 either side.
The RB.108 was also the intended powerplant for several other VTOL aircraft designs, including one by Dornier.
A similar lift jet was designed by Bristol Siddeley, the BS.59, with a thrust of 8,000 lb the engine was intended for the projected Focke-Wulf Fw 260.[2]
Applications
Specifications (RB.108)
Data from Aircraft engines of the World 1964/65.[3]
General characteristics
- Type: Single-spool turbojet
- Length: 48.3 in (123 cm)
- Diameter: 20.8 in (53 cm)
- Dry weight: 267 lb (121 kg)
Components
- Compressor: 8-stage axial flow
- Combustors: Annular
- Turbine: 2-stage axial flow
- Fuel type: JP-1
- Oil system: Non-return, total loss with metering pumps at 20 psi (140 kPa)
Performance
- Maximum thrust:
- No bleed air: 2,500 lbf (11 kN) at 17,500 rpm
- 11% Bleed air: 2,210 lbf (9.8 kN) at 17,500 rpm (4.3 lb/s (2.0 kg/s) bleed)
- Overall pressure ratio: 5.33:1
- Air mass flow: 38.8 lb/s (17.6 kg/s)
- Turbine inlet temperature: 1,346 °F (730 °C; 1,003 K) (Turbine Inlet Temperature (TIT))
- Specific fuel consumption: 1.06 lb/lbf/h (108 kg/kN/h)
- Oil Consumption: 0.4 lb/lbf/h (41 kg/kN/h)
- Thrust-to-weight ratio: 9.3
See also
- Thrust Measuring Rig
Related development
- Rolls-Royce RB145
- Rolls-Royce RB162
Related lists
References
Notes
- ISBN 0 902280 38 4, p.121
- ^ "bristol siddeley | 1962 | 1015 | Flight Archive". www.flightglobal.com. Archived from the original on 4 November 2012.
- ^ Wilkinson, Paul H. (1964). Aircraft engines of the World 1964/65 (21st ed.). London: Sir Isaac Pitman & Sons Ltd. p. 138.
Bibliography
- ISBN 1-85260-163-9
External links
Wikimedia Commons has media related to Rolls-Royce RB108.