The Tupolev Tu-95 "Bear" seems like an awfully cool piece of innovation with its unusual contra-rotating supersonic-tipped props. From what I've been reading it sounds like it's been the only mass production airplane to use props at those speeds (there were apparently a handful of American examples as test aircraft but NASA abandoned the project?).

I'm curious what profile of blades they used. I know there are lots of supersonic-capable airfoil shapes out there, but it's not clear which if any of these were used for the Tu-95 props, or even whether a fixed wing supersonic blade profile is appropriate for a prop. Any ideas?

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    $\begingroup$ Arguably, it was, in a way, something opposite: a safe bet technology chosen in preference to the true innovation: a jet engine (on a long-range aircraft). $\endgroup$ – Zeus Aug 6 '18 at 2:41
  • $\begingroup$ The TU-95 propellers are not the only ones whose tips operate at supersonic speeds. The catch is that doing so requires significantly more torque from the engine to overcome the drag from the supersonic tips. That's why the engines on the prototype TU-95's had to be discarded and replaced with more powerful ones when the aircraft entered production. I can't find any source for the airfoil used on those propellers. $\endgroup$ – Juan Jimenez Aug 8 '18 at 12:20
  • $\begingroup$ @JuanJimenez what are other examples? The XF-84H is the only other one I know of. $\endgroup$ – Aaron Altman Aug 8 '18 at 16:49
  • $\begingroup$ Every turbofan out there uses fan blades whose tips operate at supersonic speeds. The fan blades are just like propellers, except that they are "caged" in a way that overcomes the problems with propellers trying to operate at those tip speeds. Some turboprops can also operate briefly in that range but the problem is that it greatly reduces propeller efficiency and increases metal fatigue. $\endgroup$ – Juan Jimenez Aug 10 '18 at 7:50
  • $\begingroup$ The XF-84 was quite different: Spinning at 3000 RPM, most of the XF-84 prop blades' was at supersonic speed. The 850 RPM on the Tu-95 actually minimized the supersonic blade section. $\endgroup$ – Peter Kämpf Feb 1 at 15:31

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