billdunn wrote:

This may be a stupid question but bear with me.
Has consideration been given to using titanium for major components of a rotary engine ? Would it
save that much weight ?
Williams and other companies including the feds are investing alot of money in developing a small
turbine for general aviation. Willaims I have heard is having trouble with the metallurgy required
for a small diameter turbine. If they get it worked out , they will have a turbine but there are
still problems, fuel consumption, High altituden operation, IFR flight regimes (not necessarily
bad ), more redundant systems etc. Making the rotary case and rotor out of titanium might be a
relatively "low tech" solution to a high tech problem.

I have read any number of articles making the case that the best engine in the 10,000 to 20,000'
flight enviornment is turbo charged or supercharged device.

Thanks for your patience,,,any comments

bd

It is not the fed's money. Unfortunately it is yours and mine. 
I don't expect William's will give it back to us when it becomes
obvious that they have failed. What is it now two or three years
beyond schedule?

I think a titanium rotor was tried but I think the heat transfer 
characteristics were unfavorable.

Actually I think the turbo charged IC engine is pretty good
all the way up to 57,000 feet. Our man Jeff Spitzer, chief engineer
on the Predator, at General Atomics and resident rotor head got
the turbo charged Rotax 914 powered Predator up to 57,000 feet.

Back in WW II a lot of turbo charged airplanes flew up to 45,000 feet.
It was years before a jet fighter could climb to the operating
altitude of a turbo charged piston engine B36. The big improvement in
jets was when they developed intake ducts to act as ram jets
...sort of super charging the turbine engine.

Paul Lamar
 
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