Turboprop engines in WWII?

The United States in the last two years of World War II developed a number of turboprop engine designs, including the Westinghouse T30, General Electric T31 (company designation TG-100), and Pratt & Whitney JT1 (military designation T32). The JT1 was bench tested in 1943 but never flew in any aircraft before being cancelled in 1945 in favor of the advanced T34, which would be used on the C-133 Cargomaster, YC-97J, YC-124B (originally designated YC-127), R7V-2, YC-121F, and Super Guppy. The T31 began test runs in May 1945, becoming the powerplant for the Convair XP-81 and Ryan XF2R, but never entered production.

https://aviationtrivia.blogspot.com/2015/02/the-pt1-pratt-whitneys-firs…

RE: Turboprop engines in WWII?

It is probable too that there was seen to be no benfit.

Performance is limited by the speed of the prop tips.

The whole point of the jet was to give you more performance and allow the use of less well refined fuels as a bonus. The main advantage of a turboprop, reliability and life compared to a piston engine were not seen as too significant when all you wanted was an aircraft that could overhaul the enemy’s aircraft a couple of times.

The need for speed was the driving force at that time.

Moggy

RE: Turboprop engines in WWII?

Nice to know I was right about something. Sometimes I think I’m getting dumber as I get older. 🙂

RE: Turboprop engines in WWII?

Why couldn’t they vary thrust to change prop speed in the same way as they control turbojets?

I thought turbofan might be easier to make because you could do with a smaller jet engine and less thrust than 40’s turbojets.

RE: Turboprop engines in WWII?

[updated:LAST EDITED ON 14-01-03 AT 10:04 PM (GMT)]No Phantom II, your just dead right! A turbo prop is a jet engine where the gas flow is fed onto a power turbine to drive a prop instead of producing thrust. The problem was in the 40’s and 50’s that turbo props just did’nt have a sufficiently good advantage over piston engines to make them worth while. Also the big problem was the prop. A piston engine will accellerate and decellerate very quickly with throttle changes, which makes it very controllable. A Gas turbine engine likes to run at a fairly constant and high speed, which means you have to have a different type of propeller control on a turbo prop. These proved to be difficult to perfect, and it was this that really stopped the turbo prop from becoming an efficient powerplant until the late 50’s. If you take the Alliston T56 in the C-130 as an example, the engine runs at a virtually constant speed all the time, the power output (thrust) is changed by altering the pitch of the prop.

RE: Turboprop engines in WWII?

Is a turboprop really that much simpler than a turbojet? I mean when you think about it, all a turboprop is, is a turbojet with a propeller on the front. Both engines still have air intakes and the like. So by appearance the turbojet looks much more simple. Just my two cents though I’m probably way off kilter here.

RE: Turboprop engines in WWII?

the turbojet only JUST won over the turbo prop. Whittle had to convince a board that included the getn who first came up with the idea!

coanda

RE: Turboprop engines in WWII?

Turboprops were first flown in a Meteor modified to take two Rolls-Royce Trents in 1945. The problem with the early turbojets was the relatively low power output, making them unsuitable for anything other than fairly small aircraft, where the quest was for performance rather than the efficiency of a turboprop.