Miért volt Jendrassik 1937-es gépe sokkal, de sokkal fejlettebb mint a német Ohaim vagy a brit F. Whittle sugárhajtóműve?

Gykorlatilag a modern nagyhatásfokú axiális kompresszoros sugárhajtóművet, és annak számítási mechanizmusait ő találta fel, nem is jelentek meg addig nagy hatásfokú sugárhajtóművek, míg az 1950-es évek végén és a hatvanas években nem használták az ő kompresszorát.

The Jendrassik design was significantly different from other ww2 era jet engine designs, and has a lot of features of modern post-war era engines.

These included:

A rigid compressor-turbine rotor assembly carried on front and rear bearings.

There was a single large annular combustion chamber, instead of the many small combustion canisters of ww2 era jet designs. (The modern annular combustion chamber had much higher efficiency, however this design was very laborious everywhere in the world, and its precise perfect form and implementation succeeded only after long years of many costly experiments during the post WW2 era.)

It had reverse-flow configuration to shorten the engine,

It had air cooling of the turbine discs and turbine blades with extended roots to reduce heat transfer to the disc.

The annular air intake surrounded a reduction gear for propeller drive takeoff,

The exhaust duct was also annular.[1]

High efficiency axial-flow compressor: Funnel shaped house for the compressor, the first compressor disk was the biggest and each disks followed it were smaller than the previous one. In the early ww2 and post ww2 era axial jet designs (like the Jumo engines), all compressor disks had the same size, which reduced the efficiency of the air compressor.

The scaled-up version in 1941

With the predicted output of 1,000 bhp at 13,500 rpm the Cs-1 stirred interest in the Hungarian aircraft industry with its potential to power a modern generation of high-performance aircraft, and construction was begun of a twin-engined fighter-bomber, the Varga RMI-1 X/H, to be powered by it.

The first bench run took place in 1940, becoming the world's first turboprop engine to run. However,combustion problems were experienced which limited the output to around 400 bhp.[2]

Work on the engine stopped in 1941 when the Hungarian Air Force selected the Messerschmitt Me 210 for the heavy fighter role, and the engine factory converted over to the Daimler-Benz DB 605 to power it. The prototype RMI-1 was later fitted with these engines in 1944.

Causes of failure in the large scale version

The output power of the engine was smaller than it was expected from the calculations. Despite the calculations were correct, Jendrassik met with serious industrial obstacles: The lower precision of the available contemporary manufacturing technology of the ww2 era. Above all, the low heat resistance of the materials available at the time, especially in the case of the high efficiency single annular combustion chamber, which had to resist more stress than the simpler lower efficiency but more viable canister combustion chamber designs of Germans and Brits. After the war, with many years of development in metallurgy and increasing precision in metalworking, the high efficiency annular combustion chamber became the hegemonic way to build modern jet engines.

Aftermath in the American and British jet designs

His early inventions like "Rotor for gas turbines and rotary compressors" ( patent number: US2213940A ) and ( US2241782A ) patent on axial-flow compressor had a great impact on the development of the axial-flow type jet engine technology: The General Electric, Rolls Royce, Curtiss Wright Corp, Douglas Lloyd Lockhart, English Electric Co, Bristol Siddeley Engines, Vickers Electrical Co, Power Jets Res & Dev Ltd, United Aircraft Corp, Thompson Prod , General Motors Pratt & Whitney and Lockheed Aircraft Corporation companies assigned his patent ideas between the 1950s and 1980s.