NASA's New Plane Design Could Save Fuel and Money

NASA's New Plane Design Could Save Fuel and Money

Well that's interesting.

NASA will be working with aircraft manufacturers on this new design.

If I understand this correctly. They will be putting another engine on the back, electric; powered by the engines on the wings, that will ingest slower boundary layer air and expel it out the back. And doing this will increase fuel economy. And as an added bonus the engine in the rear will reduce the need to have large engines on the wings. So they can be smaller, further reducing drag and saving fuel.

This will be interesting to see if they put it in new aircraft.

NASA is best known for building rockets and spacecraft, but don't forget that "space" represents only one of the letters in the acronym. NASA also focuses on aeronautics, which means it's continually trying to improve the planes we travel in every day.

The most recent idea is called STARC-ABL, which stands for "Single-aisle Turboelectric Aircraft with an Aft Boundary-Layer propulsor." It's a terrible acronym, and for such a long-winded phrase you might expect something fancier than what it really is: an engine on the back of the plane.

a reply to: grey580

Wow, if they get this workable, those savings are huge

They could save time and money by taking a 727 and installing the electric motor in the 16 foot "S" duck where the number two engine resides... That is the center engine air duck on top of the fuselage. They might have to rework the number 1 and 2 generators to produce a tad bit more electric power but that would give them a working model on the cheap... as if anything in aviation is cheap...just relative...

a reply to: 727Sky

The point of this is to work with the boundary layer. A 727 would require extensive modification to do that. They'd lose any possible savings in the modification.

This is cool. I would have thought that most of the boundary layer would have gone turbulent by that time, but perhaps with the "suction" created by that fan, it can keep the boundary layer laminar and reduce the drag around the fuselage. Combined with a better designed wing (a la 787) drag reduction can really help fuel burn.

Wonder if someday they can make a dynamic empennage that reduces drag aloft when air is slightly more stable. That giant tail could be reduced in drag too.

originally posted by: Zaphod58
a reply to: 727Sky

The point of this is to work with the boundary layer. A 727 would requir e extensive modification to do that. They'd lose any possible savings in the modification.

There are other problems, too. The 727, with its Pratt JT8-D Stage 2 engines is too noisy to meet Stage 3 requirements. The hush kits needed to get these engines legal cost more than the 727 that you would put the mod on. At my airport, there are 4 727s being turned into beer cans because they are worthless. And they are 1950's technology. On most big jets, on final approach you call for "flaps 20" or 8 or full. On the 727, you call for "partial wing disassembly." It has slats, slots, flaps and spoilers. You can see through the damn wing on final. The good news is that from the cockpit, you can't see the wings. Also, with the wing design, you have to descend at almost full power to keep the thing in the air. When I was flying the 727, we had a saying, "If you pull the power back to flight idle and want to see where you will land, throw a brick out the window and you will land just behind the brick." And you are right that there is no laminar flow for the No. 2 engine to exploit. The 727 was the fastest thing in airline service. It was a joy to fly (most of the time.) But they are all old and worn out, kind of like its pilots.

a reply to: cosmania

They've been doing a lot of work with boundary layers in the last few years. They've found some interesting things about it, and they seem to have found a way too keep it from going turbulent until it's all the way back by the tail. It's made for some pretty interesting reading, but it gets incredibly technical at times.

It seems the extra drag on the engines from the two generators would offset the gains made by the electric motor/turbine assembly in the back.

Who is going to benefit from the savings? You can bet it won't be the tax payer.
a reply to: grey580

a reply to: gimcrackery

Many NASA innovations have made their way to commercial aviation, outside of the probably hundreds of things we've gotten from the space program. Boundary layer control has been something aircraft designers have been after for a long time. It would make aircraft quite a bit more efficient and would be a huge leap for commercial aviation.

a reply to: F4guy

OMG! I remember flying aboard a 727 and I remember being able to see through the wing.

lol

Given that aerodynamics and hydrodynamics are similar fields, what can be applied to aircraft could be applied to submarines as well. What if they could have several "ring" fan blade engines that are mounted at locations along the fuselage?

The problem with this BLI engine (Bundary Layer Ingestion) is that they haven't got the material strong enough to handle the different pressures around the tail.

www.nasa.gov...

a reply to: F4guy
727 fastest aircraft in commercial aviation? I believe that distinction goes to the Convair 880 easily capable of breaking the sound barrier, according to ex-military pilots she handled like a fighter. The 880 preceded the 727 by a few years so perhaps the 727 was the fastest of it's era, but not of all time.

originally posted by: bladerunner44
a reply to: F4guy
727 fastest aircraft in commercial aviation? I believe that distinction goes to the Convair 880 easily capable of breaking the sound barrier, according to ex-military pilots she handled like a fighter. The 880 preceded the 727 by a few years so perhaps the 727 was the fastest of it's era, but not of all time.

The fastest airliner of all time had to be the Concorde. The Convair 880 had a nominal top speed higher than the 77927, but the 4 engines, which were the civilian version of the GE J-79, used so much fuel that a reduced power setting was used which resulted in a slower normal cruise. The Convair was a failure as an airliner and only 65 were ever built, compared to 1,827 727s.

Apparently the flying wing design is the most efficient.
But the simple reason that airlines don't adopt it is because all the runways in the world would have to be widened.
I think it would be worth it for the fuel savings.
Also more efficient electric aeroplanes will come eventually.

a reply to: Dr X

There's also the problem of passenger comfort involved.

Someone answer me this. The answer to put a smaller engine to reduce fuel consumption?? Surely the engine size is dictated by the supposed load of the aircraft and the power needed to take off and land, these times when this full power is needed?
So a smaller engine would be underpowered for the task because the help of the electric engine would not come into effect till virtually cruising speed and that is when the normal engines are powered down anyway.

a reply to: crayzeed

If you can get more efficient at generating lift, you'd need less power to get airborne, even with a heavier aircraft. It's all about efficiency.

a reply to: grey580

InB4 cratering fuel prices continue to make expensive unproven new fuel-saving technologies a complete nonstarter in the commercial aviation world.

I mean, Boeing is even considering restarting 767 production because new 787 orders are so sluggish.

a reply to: Zaphod58

One of the X planes had many thousands or tiny ports on the wings for boundary layer control. It worked but it was very labor intensive to keep them all clean and working.