The Jet Age - Germany
The jet age in Germany began with the award of patent 317/38 to Hans Joachim Pabst von Ohain on the 10th November 1935. It is impossible to know how much his work was influenced by Sir Frank Whittle's patent published in 1930 although there is no doubt that even if influenced by Whittle, von Ohain deserves enormous credit for his contribution to the development of the turbojet. In April 1936 Ohain began working for Ernst Heinkel who saw great potential in his work and funded a laboratory for his development work, in September 1937 this resulted in the first successful run of the prototype Heinkel S2 hydrogen-powered turbine.
At BMW, Dr Hermann Ostrich led a research team developing the axial flow P.3302 (Later redesignated the BMW 003). This was expected to produce 1,320lbs of static thrust increasing to 1,580lbs at 560 mph. In competition at Junkers was Dr Anselm Franz who led the team developing their own 1,500 lb axial flow turbojet designated the T1, it was a much simpler design than the BMW variant with the intention of making it easier to mass produce than the BMW variant.
|
|
At Heinkel, von Ohain was well ahead, he even beat Whittle into the air with the first flight of the HE178 on the 27th August 1939. This was powered by the Heinkel S3B, a conventionally fuelled development of Ohain's first hydrogen powered turbojet engine. The HE178, like George Carters Gloster E28/39 Pioneer was never intended to be anything other than an experimental design and to prove the concept of jet propulsion. The He S3b was not a powerful engine, only capable of 990 lbs of static thrust at 13,000 rpm yet still having a diameter of 0.93m, length of 1.48m an weighing in at 360kg.
In late summer 1938 the Technisches Amt (Technical department) of the Reichsluftfahrtministerium (RLM, German Ministry of Aviation) approached Willy Messerchmidt & Ernst Heinkel to study the feasibility of building a jet powered aircraft, significantly they did not specify what the role of the aircraft would be expected to perform, leaving that choice to the manufacturers. Messerchmitt elected to use the BMW-003 for their aircraft as they believed it would be ready first, finally settling on a twin jet design due to the limited power expected from the new engines.
It was initially designed around the Axial Flow BMW003 turbojet with an entirely different layout to the Whittle engine. In the axial flow turbojet air is compressed after entering the front of the engine by a series of compressor stages or fans, in the middle of the engine fuel is added and the mixture ignites, the rapidly expanding gases then pass through a turbine connected to the forward compressor stages before exiting the jet pipe. The design has the advantage of having a much smaller cross-section although it does suffer much more if debris are ingested into the engine.
The Jumo 004 axial flow turbojet engine
The Messerchmitt design, designated the P.1065 evolved through many layouts as more was learned from BMW about the powerplant. The early idea to use a single engine was eventually abandoned because the engine was not likely to be powerful enough to give a single engine design enough speed. It ended up as an all metal, low wing twin engine design with the engines embedded in the wings at a quarter span. The solution adopted for the Meteor F9/40 with its 'Banjo' main spar was not needed because at that time the BMW engine was much smaller than it subsequently ended up being. The P.1065 won the competition although merit was also seen in the Heinkel design which went into production as the HE280.
- Further reading