Comments on: Ultra High Bypass Jet Engine Green Technology Airline Flight Test

By: Dutchdrummer99

Dutchdrummer99 — Tue, 09 Mar 2010 04:34:50 +0000

So why are these engines not used today in the high priced oil market?…

By: aerospacenews

aerospacenews — Tue, 09 Mar 2010 03:35:58 +0000

More advanced versions are coming soon from P&W and GE. The price of fuel did not increase enough in the early 90s to drive use – plus – there were concerns about noise and cost and public perception (back to “props”).

By: stephenopoly

stephenopoly — Tue, 09 Mar 2010 03:09:39 +0000

I remember reading about this many many years ago, I thought their was a noise issue in the cabin with this kind of engine? It could have been just the oil company’s making stuff up?

By: aerospacenews

aerospacenews — Tue, 09 Mar 2010 02:57:11 +0000

I believe you are correct about cabin noise but they were saying at the time that could be addressed with treatements to the plane and tip speed/shape. The 2009 projects are all shrouded like conventional fanjets – they are not unducted like the story here – but the bypass ratios are very high as attempted before.

By: maltouch

maltouch — Tue, 09 Mar 2010 02:13:15 +0000

Agree noise was a major problem for the back props specially with the two stage configuration demonstrated. in the a turbo-Fan configuration the diffuser inlet and specially the exhaust mixer at the end of the engine helped improved a lot the acoustics and increased engine performance at the same time.

By: Dutchdrummer99

Dutchdrummer99 — Tue, 09 Mar 2010 01:30:26 +0000

“More advanced versions are coming soon from P&W and GE”.

Very interesting. I also see stories from time to time about hydrogen powered engines for planes. Of course there are cooled liquid hydrogen powered engines and Fuel-cell powered. Is any of this tested by P&W and GE as well?…Thanks.

By: Outlaw1257

Outlaw1257 — Tue, 09 Mar 2010 01:16:47 +0000

Since the 1990′s, the Piaggio Avanti II has become a significant player in the GA markets, and from the inside, they are very quiet birds.

The square wave sound of the engines is quite pronounced, but IMO, not objectionable as the roaring of jet engines
.
Could that same technology be used for air liners??

By: aerospacenews

aerospacenews — Tue, 09 Mar 2010 01:12:05 +0000

Thanks for the comment! The beautiful Avanti (and it is beautiful) is using aft facing turboprops – nothing too exotic as far as I know. I think the blade tips are aft of passenger accomadations in the cabin which may be why it is quiet inside. Outside they remind me of a big Rutan LongEz. Open Rotor Jets and Ultra High Bypass Turbines are outgrowths of this core technology me thinks.

By: gigagdragoon2345

gigagdragoon2345 — Tue, 09 Mar 2010 00:54:03 +0000

finally it came

By: poptartpencil

poptartpencil — Tue, 09 Mar 2010 00:18:24 +0000

now we have devices that help reduce noise and their are new designes coming out soon such as easyjet’s new ecojet