Rolls-Royce Merlin
| Rolls-Royce Merlin | |
|---|---|
 Rolls-Royce Merlin 23 |
|
| Type: | V - aircraft engine |
| Design country: | |
| Manufacturer: | |
| Production time: |
1936-1950 |
| Number of pieces: |
149,659 |
The Rolls-Royce Merlin is a 12-cylinder - aircraft engine from Rolls-Royce in a V design , the many important British and US aircraft types of World War II served as a drive. From 1941 the engine was built under license from the Packard Motor Car Company in the USA as the Packard Merlin V-1650 . Alongside the Allison V-1710, it became the most important V-engine in the Allied Air Force.
After the war, various passenger and cargo aircraft were equipped with this engine. The civil use of the Merlin was limited, however, as it was considered robust but too loud .
According to the Rolls-Royce tradition of the time , the name of the engine was taken from a species of bird, the merlin falcon and not, as is often assumed, from the magician Merlin .
history
development
As a private project PV-12 started, it was first in 1935 in a Hawker Hart - biplane built and tested. The Merlin had a displacement of about 27 liters. The first versions of the engine developed around 1000 hp, the last around 2000 hp. The engine turned out to be a successful and reliable construction.
Military operation
The Merlin made during World War II and in the key British fighter aircraft Boulton Paul Defiant , Hawker Hurricane , Supermarine Spitfire and De Havilland DH.98 Mosquito and the Navy aircraft of the Fleet Air Arm as Fairey Barracuda and Fairey Fulmar for propulsion, and later in bombers as Fairey Battle , Armstrong Whitworth Whitley , Vickers Wellington , Avro Lancaster and Handley Page Halifax .
The Royal Air Force initially operated the Merlin with the usual to 1940 87- octane - fuel , but could in the course of the year by the United States delivered 100-octane fuel change and significantly increase through this better quality performance of the engine at low altitudes . In the course of the war, further increases in performance were achieved through the introduction of fuel additive . From autumn 1944 onwards, when using 100/150 octane fuel, it was possible to increase the maximum permissible boost pressure to 25 psi (this corresponds to 1.724 bar) and thus significantly improve performance at low and medium altitudes without great design effort.
In the USA, the Packard engine was manufactured under license under the name Packard Merlin V-1650 and, for example, in the US Curtiss P-40 Warhawk and North American P-51 Mustang , but later also in British aircraft such as the Spitfire Mk.XVI and the bombers Avro Lancaster, De Havilland Mosquito and the later further development De Havilland DH.103 Hornet .
After the Second World War, the two Spanish companies Hispano Aviación and CASA used the Merlin 500 as a drive for the HA-1112 (licensed construction of the Messerschmitt Bf 109 ) and the CASA 2.111B, a licensed construction of the Heinkel He 111 . Machines of these types can be seen in the film Battle of Britain, among others.
External distinguishing features to the German originals are the beefier engine fairings and, in the HA-1112, the exhaust pipes located above instead of below, since the Merlin V engine was not installed "hanging" ( crankshaft above) like the German aircraft engines , but upright. A CASA 2.111B is located in the Flugwerft Schleissheim , a branch of the Deutsches Museum near Munich.
Civilian use
After the Second World War, various passenger and cargo planes were equipped with the RR Merlin, such as the Avro Lancastrian , Avro Tudor and Avro York , and later the Canadian Canadair C-4 (converted Douglas C-54 ). The civil use of the Merlin was limited, however, as it was considered robust but too loud. In addition, for this reason, the engine was unable to prevail on the civilian market against the tried and tested powerful supercharged US radial engines from Curtiss-Wright and Pratt & Whitney .
variants
The most important Merlin series:
- II, III, XII: entrance loader (e.g. Supermarine Spitfire I / II)
- 20 series: improved high-altitude performance thanks to the two-speed loader (e.g. Hawker Hurricane II, Mosquito IV)
- 40 series: improved overall performance due to enlarged input loader (e.g. Spitfire V)
- 60s and 70s series: improved altitude performance thanks to two-stage two-speed loader (e.g. North American P-51B Mustang)
- 200 series: US Packard V-1650 engines (e.g. Spitfire XVI, Curtiss P-40N Warhawk, North American P-51D Mustang, Avro Lancaster)
- 500, 600 and 700 series: Post-war models of the Merlin, often for civil use
License versions
- Packard Merlin V-1650 - built by Packard in the USA from 1942 and also delivered to Great Britain
Technical data (Merlin 61)
- Type: liquid-cooled 12-cylinder - four-stroke - V-engine with 60 ° bank angle and mechanical charging
- Valve gear : four valves per cylinder, each cylinder bank via an overhead camshaft and rocker arms actuated exhaust valves sodium-cooled
- Bore : 5.4 inches (137.2 mm)
- Stroke : 6 inches (152.4 mm)
- Displacement : 27.04 l
- Dry weight: 745 kg
- Compression: 6: 1
- Output: 1170 kW (1565 hp) at an altitude of 3740 m; 1035 kW (1390 PS) in 7170 m at 3000 rpm
- Supercharging: two-stage two-speed radial compressor with charge air cooling
- Mixture formation : ascending flow double carburetor , arranged at the rear under the charger
- Lubrication: dry sump with one pressure and two return pumps
- Propeller gear : single-stage, straight-toothed spur gear
Varieties
From the Rolls-Royce Merlin derived Rolls-Royce Meteor from, basically an on (depending on version) 600-650 or 810 hp throttled Merlin to drive tanks . This turned out to be very reliable.
From Meteor turn derived Rolls-Royce Meteorite from, a downsized to 18 liters eight cylinder - V - gasoline engine , the heavy tank transporters Thornycroft Antar served as propulsion.
