Comments by "Bo McGillacutty" (@Mrbfgray) on "This Genius Invention Could Transform Jet Engines" video.

  1. Gary C OK. If you were just funn'n than I shouldn't take it literally. However I think it's a safe bet that turboprops could also greatly benefit from a big differential in turbine versus prop RPM, for what it's worth....without considering the down side of higher cost, weight, maintenance, etc. (Sorry, I can't help but be fascinated by the engineering particulars that's why I clicked on the vid :-) )
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  2. Gary C Variable pitch and bypassing the combustion chamber with most of the thrust producing air are related but separate aspects. Again, turbofans have been 'emulating' turboprops in this way for half a century. (I believe it was the 747 that accelerated the adoption of high bypass efficiency) Apparently the difficulty comes about when attempting to gear the rotational speed differential along the same axis, hence requiring some sort of planetary arrangement where as turboprops have an offset prop shaft geared to the turbine shaft greatly simplifying the gearbox. Right?
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  3. Gary C Pardon me pressing the point then, but I have learned a couple things here since I was not near as aware of the particulars of turboprops as airliner engines. Thanks for the discussion.
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  4. Does the PT-6 (or any other turboprop, turbo anything) have multi speed shaft? High bypass engines are half a century old but all had/have single speed shafts. It sounds like you are confusing turbofans (old tech) with geared turbofans. I don't know what's "genius" about it, just an obvious, long wanted but difficult to solve engineering problem.
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  5. Gary C Very generous of you. ;-)
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  6. Now fire a frozen TURKEY at mach 0.7 into engine whilst at full power! :D
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