Unknown (almost) german WW2 turbojets

[Wurger]

Hi,

I have collected through the years some references on some obscure turbojet projects. Those are a turboprop developed by the TH Berlin in the late 1930`s, stated by Manfred Griehl. I tried to contact the successor to that institution, but all their records were destroyd in the war.

Also a high output axial turbojet undertaken by Herbert Wagner after 1940, when he went to Henschel. According to David Myhra it reached the axial compressor stage construction phase.

Does anyone have some input on this subject?

 

[tartle]

The best information I have found on the early years of German GT development is contained in 'Aeronautical Research in Germany- from Lilienthal to Today'. There is a summary table on page 228 which I have copied below. Horst Prem gave a lecture in German based on the book and the lecture slides include the table in German which can be downloaded here... fascinating sweep of German technological development in the last century.
The book discusses the relationship of axial compressor design to wing design 'a la Prandtl' (the different approach taken by Britain who went along for years with no theory of lift and Germany who 'mathematicised' Lanchester's vortex insights was covered in David Bloor's 'Enigma of the Aerofoil') ... with axial compressor stage test results being available to German engine people in the early '30s. Contrast that with moving Griffith away from RAE in late twenties after he had the insight that a compressor was not a series of channels but a series of aerofoils, which left us years behind compressor understanding. Thank goodness Whittle realised more rapid short term progress could be made with the centrifugal! The USA had another way of designing their axial compressors based on isolated wing theory and backed it up with compressor testing... but at end of WW2 all three nations had compressors roughly equal in capability (aerodynamically). Metrovick were able to build a series of rigs that increased their knowledge and with some insights from a GTCC visit near the end of the war they eventually designed the Sapphire compressor- good aerodynamically but not without its structural issues. RR by contrast tried to build on the limited RAE results and came up with the Avon which had major aerodynamic issues... when they were given the aerodynamic results from (by then) Armstrong Siddeley -in return for structural and vibration insights- the rigs with AS technology were little better than existing RR results. It was not until a redesign of the engine (not just the compressor) that there was a major step forward in the behaviour of the compressor.

 

[Wurger]

Hi tartle,

I have Antony Kay`s book "German jet engine and gas turbine...", which is pretty good, but Antony has this oppinion that everything is already told on the german side of jet engines. He never heard about the projects I refered in the first post. He although mentions Weinrich`s projects, not otherwise known and worth a good research.

 

[Grey Havoc]

On a related note: http://www.telegraph.co.uk/news/2016/05/08/sir-frank-whittles-son-accuses-whitehall-of-marginalising-jet-en/

 

[Rickshaw]

On a related note: http://www.telegraph.co.uk/news/2016/05/08/sir-frank-whittles-son-accuses-whitehall-of-marginalising-jet-en/

*SIGH*, so many inaccuracies...