wuzak
Captain
In 1940 Junkers Moteren (Jumo) began the development of a steam turbine for use in multi-engine aircraft. The steam turbine ran on the bench in mid 1941 before being cancelled by the RLM in 1942 in favour of gas turbines.
There was interest from Messerschmitt in installing the steam turbine in the Me321 transport glider.
The specs for the Jumo steam turbine was 3000hp @ 8000rpm, prop shaft speed 950rpm, pressure 100atm, exhaust pressure 0.15atm. Weight 800kg, I assume just for the turbine and reduction gear.
Also in the same period the Technische Hochschule were developing a 4000hp steam turbine for aircraft use, but this too was cancelled in 1942.
In 1944 the Osermaschinen company was commissioned to develop a steam turbine for use with the Me264 long range bomber. The design requirements specified 6000hp @ 6000rpm for the turbine, a power to weight ratio for the entire installation of 0.7kg/hp and a sfc of 190g/hp/hr (0.42lb/hp/hr). There was to be two propellor options - a 5.3m (17ft 4.5in) diameter prop turning at around 500rpm, or a 2m (6ft 6in) diameter prop turning at 6000rpm.
The plan was to use 65% pulverised coal/35% liquid fuel while liquid fuel stocks were low, but to use 100% liquid fuel when sufficient quantities were available.
Parts of the turbine had been manufactured by the end of the war in Europe, but it had not run and the Me264 prototype that was to use it had been destroyed.
The advantages of steam turbines were:
Time between overhauls as much as 10 times that for piston engine (ie 4000-6000 hours tbo).
Constant power at varying heights.
Capacity for 100% overloading for extended periods (ie on a 3000hp engine you can go to 6000hp WEP, or on a 6000hp engine you could go to 12,000hp).
Full steam output in 5-10s (I presume from startup)
Not sensitive to low temperatures.
Simple control.
Poor quality fuels could be used
In comparison to the new gas turbines being developed the steam turbine promised to be much more fuel efficient.
On the downside, I don't think high pressure boilers would take too well to being hit by cannon shells, or even mg shells.
If the Junkers and the Technische Hochschule projects were not cancelled it may have been possible that they would have been available during 1943/1944.
With so many German designs perhaps not having the power required, and fuel shortages cutting into operations could steam turbines have provided a useful interim step between piston power and gas turbines?
Bearing in mind that gas turbines were relatively new, while steam turbines had been around in industry and shipping for the best part of half a century.
There was interest from Messerschmitt in installing the steam turbine in the Me321 transport glider.
The specs for the Jumo steam turbine was 3000hp @ 8000rpm, prop shaft speed 950rpm, pressure 100atm, exhaust pressure 0.15atm. Weight 800kg, I assume just for the turbine and reduction gear.
Also in the same period the Technische Hochschule were developing a 4000hp steam turbine for aircraft use, but this too was cancelled in 1942.
In 1944 the Osermaschinen company was commissioned to develop a steam turbine for use with the Me264 long range bomber. The design requirements specified 6000hp @ 6000rpm for the turbine, a power to weight ratio for the entire installation of 0.7kg/hp and a sfc of 190g/hp/hr (0.42lb/hp/hr). There was to be two propellor options - a 5.3m (17ft 4.5in) diameter prop turning at around 500rpm, or a 2m (6ft 6in) diameter prop turning at 6000rpm.
The plan was to use 65% pulverised coal/35% liquid fuel while liquid fuel stocks were low, but to use 100% liquid fuel when sufficient quantities were available.
Parts of the turbine had been manufactured by the end of the war in Europe, but it had not run and the Me264 prototype that was to use it had been destroyed.
The advantages of steam turbines were:
Time between overhauls as much as 10 times that for piston engine (ie 4000-6000 hours tbo).
Constant power at varying heights.
Capacity for 100% overloading for extended periods (ie on a 3000hp engine you can go to 6000hp WEP, or on a 6000hp engine you could go to 12,000hp).
Full steam output in 5-10s (I presume from startup)
Not sensitive to low temperatures.
Simple control.
Poor quality fuels could be used
In comparison to the new gas turbines being developed the steam turbine promised to be much more fuel efficient.
On the downside, I don't think high pressure boilers would take too well to being hit by cannon shells, or even mg shells.
If the Junkers and the Technische Hochschule projects were not cancelled it may have been possible that they would have been available during 1943/1944.
With so many German designs perhaps not having the power required, and fuel shortages cutting into operations could steam turbines have provided a useful interim step between piston power and gas turbines?
Bearing in mind that gas turbines were relatively new, while steam turbines had been around in industry and shipping for the best part of half a century.