Extreme Speed Prop Planes Discuss the need for speed with fast prop planes (Screamin Demon, Diamond Dust, Shrikes or any REAL sound breakin'''' plane)

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Old 11-15-2004, 10:17 PM
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Default PropFan

Has anyone ever designed a propfan as a substitute for prop for extreme speed planes? Seems that with the bent blades the sonic tip speed can be postponed, and instead of 30+K RPM the engine speed limit may be 40+K with the same prop(fan) diameter. Bending (only) the tip backwards is typical of full size helis.

Propfan can also work with Turbines - seems that extreme speed prop planes have a slicker design than jets because there's no need for a large air tube. Since R/C micro turboshaft engines exist (for turbine R/C helis), they could be imported by a propfan plane. And it would still be considered a prop plane... with 300MPH top speed.

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Old 11-16-2004, 10:47 AM
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Default RE: PropFan

for piston power...... are you basically refering to a ducted fan ???? those are nothing really new. Been around for years.

You are right, you can approach some insain RPM with a 5" fan diameter. The problem is, the piston engines have a tough time handling much over 26K rpm. There are a small handfull of model piston engines (40 size and larger) carefully crafted to get up to around 30K rpm........but they are very rare.

For turbines....... I have seen a few photos of turbo-fans that are being tested. They look real nice! From what I can gather they are twin spool similar to the turbo-shaft/turbo-prop engines that are out there.
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