View Full Version : Ceramic Turbines
Camp Freddie
29th Oct 2003, 23:43
About 5 years ago more than 1 person told me that research was under way into ceramic turbine blades that could withstand much hotter temperatures, the idea being that an overtemp on start would not be such a big deal as it is now and also that the engine would be able to run hotter generally allowing it to produce more power assuming within N1/Ng and torque limits.
but I havent heard anything since !
did I dream this? any progress? any working examples? when are we likely to get this in production? or is it all just nonsense?
ShyTorque
30th Oct 2003, 02:32
Ceramic turbines?
They made three prototypes but there were big problems with them. One wasn't ovenproof and the pattern came off another in the dishwasher. The third was dropped while it was being dried up and it smashed on the kitchen floor ;)
Bladestrike
30th Oct 2003, 05:38
The US Coast Guard was quite fed up with the old tank engines, the Lycoming LTS 101, that they had in their Dauphins, and made a stink, sending the manufacturers back to the drawing board, and voila, the ceramic blade was the result.
Actually I'm not sure if its a Lycoming invention, but it is a mod they've been offering for the LTS101 for quite a few years now, at least on the 222 and Dauphin, and it certainly reduces the maintenance on those engines, but at quite a cost.
Ceramic coatings are increasingly common on turbines.
NickLappos
30th Oct 2003, 10:09
Ceramic coatings are one solution, but entire blades are quite another. We are generally informed of new happenings by the folks who are attmpting them (Pathfinder, etc) where the press releases contain enough truth to allow publication, and neither reporters or the public know enough to allow balance.
Ceramic blades were tried as far back as Bill Lear and his automotive turbine (I recall watching a 1960ish Chrysler drive by at the NY World's Fair, making a whining sound (like a pilot, but not as loud!)
The need for high temp is the reason, and ceramics love that environment, but they must have great strength to withstand the centripital forces and bending strain as the aerodynamic forces press on them. Nobody has yet found the combination of temperature resistance and strength to beat the metals that turbine blades are made of. But everybody knows how to make a press release.
bellsux
30th Oct 2003, 15:21
Shy Torque... You made my day, fell off my chair laughing!! If you don't mind I will use that quote in future.:)
ShyTorque
30th Oct 2003, 15:33
Bellsux
:E :O
Bladestrike
1st Nov 2003, 07:15
I misspoke.
There is a mod for the LTS101, but's its "low flow cooled blades" designed to increase cycle life disc inspection requirements, and they are not ceramic. (Direct from Lycoming!)
Hey, its been ten years since I flew a deuce....
Nick, got a ride in the 92 last weekend (in Halifax), very impressive! Bob wouldn't let me behind the wheel though........
NickLappos
1st Nov 2003, 19:47
No offense, Bladestrike, but it could be the username set him back a bit.....
;-)
Seriously, cooling technologies are where its at these days. The idea is that air is pumped up through the blade's interior, cooling the metal from within, then passes to the surface in slots that allow it to produce a film of air to protect and cool the surface. That way the temperature of the hot gas can be many degrees higher than the temperature of the metal itself.