The Pratt & Whitney's PurePower PW1000G engine has been certified for use. Amazing that it took 20 years to develop.


http://www.pw.utc.com/PurePowerPW1000G_Engine

Interesting post Opus, thanks for putting it up.

I did find this interesting:

In the PurePower PW1000G engine family, a state of the art gear system separates the engine fan from the low pressure compressor and turbine, allowing each of the modules to operate at their optimum speeds. This enables the fan to rotate slower and while the low pressure compressor and turbine operate at a high speed, increasing engine efficiency and delivering significantly lower fuel consumption, emissions and noise.

And from the "more things change, the more they remain the same.." archives:

The Wright R3350 with "Power Recovery Turbine":


Image stolen from here:
http://www.aviation-history.com/engines/r3350.htm

I just hope that the new P&W has much better reliability than the R-3350 PRT. That thing was a night mare to keep running and to keep from being on fire.

Reduction boxes and oil seals, there is a lot there that could go wrong, but they seem to be robust... so far.

Wonder what the fail safe is on the reduction box. Will the fan blade spin should one go tits up. If not, that's a hell of a lot of parasitic drag to deal with.

It seems to be a marriage of the turboprop and the turbofan engine. That allows the fan to turn slow enough that the blade tips are subsonic, thus reducing noise. While the the turbojet core produces thrust. Since the whole thing is a ducted fan waste heat adds thrust. Pretty efficient. Much like this: https://en.wikipedia.org/wiki/Republic_XF-12_Rainbow

4 x Pratt & Whitney R-4360-31 Radial engines, 3,250 hp ea. 2 stage forced cooling and ducted heat recovery thrust plus turbo compounding. 470 mph! Imagine if they had been the later 4,300 hp versions.

Well lets hope that the PW1000G doesn't catch on fire as the R-4360 like to do from time to time.

surestrike:
the 4360 was little better
B29-3350
B50-4360
both where horrors and then change the top cylinders after 25 hours.