de Havilland Gyron Junior
| Gyron Junior | |
|---|---|
| |
| de Havilland Gyron Junior at thede Havilland Aircraft Museum | |
| Type | Turbojet |
| Manufacturer | de Havilland Engine Company |
| First run | August 1955[1] |
| Major applications | Blackburn Buccaneer Bristol 188 |
| Number built | 89 |
| Developed from | de Havilland Gyron |
Thede Havilland Gyron Junioris a militaryturbojet enginedesign of the 1950s developed by thede Havilland Engine Companyand later produced byBristol Siddeley.The Gyron Junior was a scaled-down derivative of thede Havilland Gyron.
Design and development
[edit]The Gyron Junior was a two-fifths flow scale version of the existing Gyron engine. It started as Project Study number 43 in 1954 and the first prototype ran in August 1955.[2]
It powered theBlackburn Buccaneer S.1twin-engined Naval strike aircraft. The engine was rather unreliable and considered short of thrust.[3]The later Buccaneer S.2 used the more powerfulRolls-Royce Speyengine.
The engine had variable inlet guide vanes, as used on many other engines, necessary for accelerating from idle to high thrust. However, on the Gyron Junior, positioning of the vanes was not reliable and could cause surging which, in turn, could prevent accelerating to higher thrust levels.[3]A possibly unique feature on this engine was valve-controlled cooling air to the turbine blades. The engine had to supply air for the aircraft's boundary layer control system and the resulting thrust loss was unacceptable. To regain the thrust the turbine temperature limit was raised by using turbine blade cooling, selected only with blowing on.[4]
In December 1970 a Buccaneer was lost after one engine surged and failed to accelerate on an overshoot and a week later another aircraft was lost after an uncontained engine failure. This last accident brought to an end the use of Gyron Junior.[3]
Two Gyron Juniors, with afterburners, were also used on theBristol 188Mach 2 supersonic research aircraft. The 188 was originally intended to have theRolls-Royce Avonbut the half ton lighter Gyron Junior was substituted in June 1957. This engine was one of the first with continuously variable thrust up to full reheat; others increased thrust in discrete steps.[5]The programme was terminated early without achieving the high-speed high-temperature trials that had been intended. Limitations included poor fuel consumption of the Gyron Junior and engine surging. Fuel limitations restricted the time spent at its maximum speed, Mach 1.95, to a few minutes. This was not long enough to achieve the required stabilized temperatures in "thermal soaking" tests.
Variants
[edit]Ref:[1]
- Gyron Junior DGJ.1
- (or P.S.43)
- Gyron Junior DGJ.2
- (Mk.101) Interim production stage, used on Buccaneer S. Mk.1.[6]Variable inlet and guide vane, annular manifold for flap blowing, 121 in (3.1 m) long overall
- Gyron Junior DGJ.10
- Exhibited in 1958 at Farnborough, longer than the DJG.1[7][6]
- Gyron Junior DGJ.10R
- (or P.S.50) highly augmented afterburning version for theBristol 188,dry thrust 10,000 lb, wet thrust 14,000 lb (62.3 kN). Added zero stage and two rows of variable stators. Variable nozzle with convergent, convergent/parallel or convergent/divergent configuration depending on reheat selection and aircraft speed. Overall length 191 in (4.9 m)[8]
- Gyron Junior DGJ.20
- [6]
Applications
[edit]- 40 aircraft built[9]
- Only 2 built
- Testing only, 1 production FAW Mk.1 modified[10]
- Intended application, not built
Engines on display
[edit]A de Havilland Gyron Junior is on display at thede Havilland Aircraft Museum,London Colney,Hertfordshire.
A D.H Gyron Junior is on public display atEast Midlands Aeropark.
Also on display at theGatwick Aviation Museum,Charlwood,Surrey,two running engines can also be found here, fitted to Buccaneer S.1,XN923.[11]
Specifications (Gyron Junior DGJ.10)
[edit]
Data fromGunston and Jane's All the World's Aircraft 1962-63.[1][6]
General characteristics
- Type:Single-spool after-burningturbojet
- Length:102.9 in (261.4 cm)
- Diameter:41.1 in (104.4 cm)
- Dry weight:3,100 lb (1,400 kg)
Components
- Compressor:7-stage axial flow with Variable Inlet Guide Vanes (VIGV)
- Combustors:Annular combustion chamber with 13 spill-type burners
- Turbine:Two-stage axial flow
- Fuel type:Aviation kerosene
- Oil system:Pressure spray/splash with scavenging
Performance
- Maximumthrust:10,000 lbf (44 kN) dry, 14,000 lbf (62 kN) wet at sea level, 20,000 lbf (89 kN)+ at M2.5+ at 36,000 ft (11,000 m)
- Overall pressure ratio:DGJ.1:6.4:1[1]
- Air mass flow:DGJ.1:123 lb/s (56 kg/s)
- Thrust-to-weight ratio:3.23 dry, 4.52 wet at sea level, 6.45+ at M2.5+ at 36,000 ft (11,000 m)
See also
[edit]Related development
Comparable engines
Related lists
References
[edit]- ^abcdGunston, Bill (1989).World Encyclopaedia of Aero Engines.Wellingborough: Patrick Stephens. p. 52.ISBN1-85260-163-9.
- ^Flight"Aeroengines 1960"
- ^abc"A Passion For Flying" Tom Eeles, Pen & Sword Books Ltd. 2008,ISBN978 1 84415 688 7,p.42
- ^"From Spitfire To Eurofighter" Roy Boot, Airlife Publishing Ltd. Shrewsbury<ISBN1 85310 093 5,p.133
- ^"1962 | 0700 | Flight Archive".flightglobal.Archived fromthe originalon 24 February 2016.
- ^abcdTaylor, John W.R. FRHistS. ARAeS (1962).Jane's All the World's Aircraft 1962-63.London: Sampson, Low, Marston & Co Ltd.
- ^"A New Gyron Junior"(PDF),Flight,August 1958
- ^"Aeroengines 1960",Flight,18 March 1960
- ^Jackson, A.J. (1968).Blackburn Aircraft since 1909.London: Putnam Publishing. p. 494.ISBN0-370-00053-6.
- ^James, Derek N. (1971).Gloster Aircraft since 1917.London: Putnam Publishing. pp. 322, 326, 370.ISBN0-370-00084-6.
- ^Gatwick Aviation Museum - Buccaneer S.1Archived16 March 2016 at theWayback MachineRetrieved: 23 February 2012
External links
[edit]
