Anyone know what this is???

[TrafficInSight]

The world needs more sabreliners

 

[pilotyip]

turbo-prop-fan

Someone once experimented with a single stage extremely hi-bypass 16-blade variable pitch hypersonic blade turbo fan. The blades changed angle of attack based upon performance desired. Test flew it on a DC-9 in mid-80's. It was a cross over between a turbo prop and turbo fan.

 

[Some guy]

Think of a the fan on a turbofan engine essentially being a prop.

 

[qmaster3]

powered by a gas turbine, but it would be misleading to refer to it as a turbofan..

Correct.


Four General Electric LM2500 Gas Turbine Engines (GTEs). This is why those little DDGs are so fast.

 

[crash-proof]

Someone once experimented with a single stage extremely hi-bypass 16-blade variable pitch hypersonic blade turbo fan. The blades changed angle of attack based upon performance desired. Test flew it on a DC-9 in mid-80's. It was a cross over between a turbo prop and turbo fan.

Like this?
http://www.md-80.net/SAS-MD91.jpg

Wonder why it fizzled out...too loud maybe?

 

[crash-proof]

"Turbofan engines sound pleasant"

No, they sound boring. Nothing says good morning like a CJ-610 at max power early in the am.

I agree, i remember back in the 80s used to live by DCA when them straight-pipe GIIs would take off screamin and trailin smoke, those were the days!

I'd like to take a trip to some eastern europe airport just to relive that, those ol ruskie airliners still rumble like the cold war ain't over yet!

 

[9GClub]

GE unducted fan (UDF)

http://www.aerospaceweb.org/question/propulsion/q0067.shtml

http://www.airliners.net/discussions/tech_ops/read.main/29254/6/

http://www.airliners.net/discussions/tech_ops/read.main/2783/6/


And from http://www.airliners.net/discussions/tech_ops/print.main?id=80729:



[font=ARIAL,]Topic: RE: Is There Any Aircraft That Uses An Un-ducted Fan?
Username: Okie
[font=ARIAL, Helvetica, Geneva]Posted 2004-02-03 02:41:30 and read 1837 times.[/font]

[font=ARIAL,]I think there was a lot of R & D done on that puppy and was promising until the powers that be (FAA) determined that it had to have Containment for the blades.
[/font]

[/font][font=ARIAL,]Topic: RE: Is There Any Aircraft That Uses An Un-ducted Fan?
Username: LMP737
[font=ARIAL, Helvetica, Geneva]Posted 2004-02-03 02:54:28 and read 1790 times.[/font]

[font=ARIAL,]Some of my former co-workers at Boeing Flight Test Long Beach worked on the UDF program during the MD days. They said while the engine was good on gas the noise inside the rear cabin was almost unbearable. Not exactly passenger friendly.[/font]

[/font][font=ARIAL,]Topic: RE: Is There Any Aircraft That Uses An Un-ducted Fan?
Username: GrandTheftAero
[font=ARIAL, Helvetica, Geneva]Posted 2004-02-03 08:14:39 and read 1662 times.[/font] [font=ARIAL,]Economics had a lot to do with it, too. The UDF was designed with lower SFC in mind. With the price of petroleum no longer a critical issue near the end of NASA's Advanced Turboprop Program study, airlines didn't see any reason to build airplanes with unducted fan engines.

On a related note... The SFC reduction than can be expected in future high-bypass ratio turbofan engines, such as the ones that are currently being proposed for the 7E7, will surpass the efficiency of the UDF.

--Shane[/font]

[/font]

 

[bocefus]

Oh yeah, I have a fair amount of time onboard the IL-76 many of them have "STAGE 3" stenciled on the nacelles, what a joke! Go to the Emirates or anywhere in Africa and you can see/hear plenty of them. They are becoming more and more rare in Eastern Europe and banned thoughout most western Europe.