Comments by "Piccalilli Pit" (@piccalillipit9211) on "You May Not Like It But this Is What Peak Combustion Technology Looks Like - Rotary Vane Engine" video.

16:40 I WAS LITERALLY SHOUTING "ROLLS ROYCE DO THIS WITH JET ENGINES" at the computer when you said it - I had a personal tour of the RR Derby factory in about 2004 The single best thing ever in my life - utterly amazing. The grow the compressor blades as a single crystal
115
@removechan10298 YEAH I know. They crate a ceramic mould with a long spiral on the end, they drop a tiny perfect crystal of metal, these were titanium, into the bottom of the spiral and then the pur in liquid titanium and then it goes in an oxygen free autoclave where they cool it over about 3 weeks and the crystal grows up the spiral and then forms the blade.
7
@removechan10298 The large bypass blades that you see are 3 layers of titanium sheet that they use lasers to weld together in a complex pattern welting either the top to the middle, the bottom to the middle or all three together. They then use very high pressure nitrogen to inflate the sandwich and it POPS into the exact 3D shape of the blade. Inside the centre sheet is stretched into a 3D triangulated lattice V-V-V- Honestly everyone should be able to have a tour - its AMAZING
6
@geirmyrvagnes8718 Yes they do, at high RPM the blades stretch which means at lower RPM they have to have a relatively large gap and this reduces efficiency.
3
@removechan10298 Its like an ultra-precise high-tech version of hydeo forming. The other factory I got a tour of was Toyota in Derby - that is equally as impressive for the production line, but obviously in a very different way.
3
@geirmyrvagnes8718 Dude you are COMPLETELY missing the point. The outer wall is circular - let's exaggerate. The blade is 10cm long and at 100K RPM it stretched 1cm. That means at 0 RPM is has to be 1.1cm from the outside wall and only achieves tolerance at 100k rpm on takeoff, so for the rest of the flight there is blowby and that lowers eficiency. So they create an air wall between the tip of the blade and the wall of the housing with some technology that is patented - I believe its ionised or resonant but I dont know - it was secret at the time.
1