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KarelXWB
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Airbus A340 Laminar Flow Demonstrator To Fly In 2017

Tue May 31, 2016 10:22 am

As part of the Clean Sky 2 project, Airbus plans to fly a laminar flow demonstrator in 2017. Goal is to achieve 5% fuel burn savings.

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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Tue May 31, 2016 1:49 pm

Quoting KarelXWB (Thread starter):

This is a very interesting development.
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Tue May 31, 2016 4:02 pm

How does it work?

is it like Boeing's laminar surfaces where it just is shaped to maintain laminar flow a little longer, or is it an active system?
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Tue May 31, 2016 6:32 pm

Oops, didn't see this thread before replying in the other. Covers much the same area - dunno why you didn't do them as one Karel!!

Quoting DocLightning (Reply 2):
is it like Boeing's laminar surfaces where it just is shaped to maintain laminar flow a little longer, or is it an active system?

natural laminar flow - shaping and surface finish only.
 
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Wed Jun 01, 2016 6:50 am

The A340 demonstrator rendering reminds me of the Handley Page 88. The crescent wing no doubt is part of the solution in this experiment.
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Wed Jun 01, 2016 9:22 am

Quoting zeke (Reply 4):
The A340 demonstrator rendering reminds me of the Handley Page 88.

Let's hope for a happier outcome.
 
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Wed Jun 01, 2016 5:19 pm

This project is on-going now in Tarbes, UK have a team there from Filton Design / Engineering teams.

A320 MSN1 (F-FFBA) has some Clean Sky titles applied to it at the moment, so this may be seen in the air again soon.
 
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Thu Jun 02, 2016 6:01 pm

From the photo of the poster it looks like the test airfoil will be just extensions added to the wing tips of the test aircraft, right?
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Thu Jun 02, 2016 8:28 pm

Quoting hivue (Reply 7):
From the photo of the poster it looks like the test airfoil will be just extensions added to the wing tips of the test aircraft, right?

Yes. Here's more detailed information on it, than you could ever want to you: http://www.aerodays2015.com/wp-conte...oads/sites/20/3B-1-Jens-Koenig.pdf

What I don't understand, is how this new wing geometry can be potentially this disruptive.

Is this the first time that anyone thought of this?
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Thu Jun 02, 2016 8:56 pm

Quoting rjsampson (Reply 8):
Is this the first time that anyone thought of this?

No. Check this out:

http://www.aviation-history.com/theory/lam-flow.htm

"The North American P-51 Mustang was the first aircraft intentionally designed to use laminar flow airfoils."
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Thu Jun 02, 2016 11:17 pm

Quoting hivue (Reply 7):
From the photo of the poster it looks like the test airfoil will be just extensions added to the wing tips of the test aircraft, right?

It looks rather like the wing was chopped of right outside the outer engines and replaced.
 
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Thu Jun 02, 2016 11:31 pm

Quoting hivue (Reply 9):
"The North American P-51 Mustang was the first aircraft intentionally designed to use laminar flow airfoils."

Be very careful here : There is no more "laminar airfoils" than there are "turbulent airflow airfoils".
This is the epitomical misnomer in aerodynamics : The mustang airfoil had a rather sharp front and the max thickness positionned a lot more aft of the profile than it was normally conceived ( basically just at the mid-chord position).
That it achieved much lower drag coeffs than on classical airfoils was its quality...but its lift coeff was nothing to crow about : the Mustang never was the dogfighter the Spitfire was, but it had more than twice its range....
So here, laminar should be taken as referring to a shape ( laminar ~ bladelike ) rather than real aerodynamic effect.
By the same token , the Liberator had a similar airfoil.

This thread is a bit surprising to me as I personnally started one some four or five years ago about the BLADE research... without much success.

Quoting zeke (Reply 4):
The crescent wing no doubt is part of the solution in this experiment.

I don't think so, as they are working on a lot of parameters, one being the sweep angle : at this moment, they are stuck with a Mach .75 and reduced sweep surface.

Quoting rjsampson (Reply 8):

Is this the first time that anyone thought of this?

Boeing and NASA are doing some very similar research ( and not surprisingly, a drag drop of 8% or more is not to be sneezed at )... The Europeans seem to have a narrow lead on the testing .
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Fri Jun 03, 2016 12:08 am

Quoting zeke (Reply 4):
The A340 demonstrator

Did Airbus save the tooling?  
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Fri Jun 03, 2016 8:23 am

Quoting Revelation (Reply 12):
Did Airbus save the tooling?

What tooling would that be?
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Fri Jun 03, 2016 11:17 am

Quoting hivue (Reply 7):
From the photo of the poster it looks like the test airfoil will be just extensions added to the wing tips of the test aircraft, right?

No.

It is a replacement for part of the existing wing. Almost all of the old wing outboard of the engines will be removed and replaced with a new laminar flow wing section, with different designs being tested on each side.
 
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Fri Jun 03, 2016 2:01 pm

Quoting KarelXWB (Reply 13):
What tooling would that be?

The A340-NG related tooling that now will be needed for the A340-NG-NG Laminar Edition that will clamored for in countless a.net posts, once this news becomes more widely circulated. 4-Engines-4-Longhaul-4-Ever!
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Fri Jun 03, 2016 3:39 pm

Laminar flow wings are still in there infancy. It is a question of how much laminar flow and the stall risk.

What is new is the features to limit the severity and spread of a stall.

All aircraft have laminar flow wings for transport aircraft today. They have 30% to 40% top-side laminar flow and 5% to 10% bottom-side. The wings also have compromised cross sections to mitigate stall characteristics.

What is changing is the amount of laminar flow top-side, adding much more bottom -side laminar flow. and new features that mitigate stall onset, stall propagation, and improve stall recovery.

Take the Global Hawk, it has normal bottom -side laminar and about two thirds top-side. When the Global Hawk stalks, it will spin and crash. Stall recovery is incredibly difficult and flight control soft spends an incredible amount of time avoiding stalling. No human pilot could fly a Global Hawk and no service would accept that wing's risk in a manned plane.

Quoting rjsampson (Reply 8):
What I don't understand, is how this new wing geometry can be potentially this disruptive.

Is this the first time that anyone thought of this?

In the last decade, many new stall avoidance and stall recovery features have been developed. For example, my employer bid a wing several percent more efficient than what we're discussing here.

Some required better manufacturing processes. A riveted aluminum wing is listed to about 50% top-side laminar flow due to surface condition. All of the R&D is CFRP wings. While much can be done with aluminum, there is a limit due to joining technology.

Quoting hivue (Reply 9):
The North American P-51 Mustang was the first aircraft intentionally designed to use laminar flow airfoils."

About 30% top-side laminar flow at elite squadrons with hand worked airframes (batch selection of parts too). Normal squadrons were about 20% top-side laminar and lesser 'batch-selected' engines meant they were 6 to 8 knots slower in the non-elite squadrons.

Note:. Every nation in WW2 had elite squadrons that received the best equipment. For example, every Merlin engine was acceptance tested. Those in the top 5 or so percent of those built went to the best fighters to the top 'elite' squadrons. The next tier down went to the best fighter type, but the regular squadrons. The next tier down went to other fighters (E.g. Hurricanes), and so on down to 5 engine bombers. The same was true of airframes. If an airframe tested faster, the engine was replaced with a better engine and dispatched to an elite squadron.

For the Mustang, about 5% of airframes were built to tighter tolerances and better craftsmanship. Those planes took multiple more labor hours to build. Those are the airframes that made the P-51 famous. Training squadrons received planes at the other end if the spectrum. There is a reason ME109 or FW190 fighters could shoot down some P-51s, that is because not all were built to top standards. "Elite" planes had that 6 to 8 knot advantage which made a significant difference.

Secondary theaters would also receive lesser planes with worse laminar flow wings.

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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Fri Jun 03, 2016 4:00 pm

Quoting Pihero (Reply 11):
Quoting lightsaber (Reply 16):

Thanks much for the very informative posts.

Quoting lightsaber (Reply 16):
What is new is the features to limit the severity and spread of a stall.

I am guessing the stall speed and severity is elevated because the airflow over the wing is more "perfect" or "ideal," and so when the airflow finally breaks down at a high enough AoA and the wing stalls it's that much nastier.
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Fri Jun 03, 2016 4:23 pm

Quoting Revelation (Reply 12):
Did Airbus save the tooling?

It's at Area 51, next warehouse over from the 757 jigs and tooling.   

On subject: Does this design create any stability issues? I may be reaching a bit, but I seem to recall that the American Yankee AA1 had some rather nasty handling characteristics due to a laminar flow design. This was changed int he AA1A. The plane lost some speed, but stability was increased.

"Quoting KarelXWB (Reply 13):
What tooling would that be?

"The A340-NG related tooling that now will be needed for the A340-NG-NG Laminar Edition that will clamored for in countless a.net posts, once this news becomes more widely circulated. 4-Engines-4-Longhaul-4-Ever!"

And, QR is the launch customer.  duck 

[Edited 2016-06-03 09:25:55]
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Fri Jun 03, 2016 5:21 pm

Great development but what I don't understand is why this is all happening now.

If we are talking about shaping and surface finish only, and no active laminar flow systems, what critical technology is enabling these latest significant gains in the extent of laminar flow? Computational aids or manufacturing innovations or what exactly?


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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Fri Jun 03, 2016 7:15 pm

Quoting lightsaber (Reply 16):
Take the Global Hawk, it has normal bottom -side laminar and about two thirds top-side. When the Global Hawk stalks, it will spin and crash. Stall recovery is incredibly difficult and flight control soft spends an incredible amount of time avoiding stalling. No human pilot could fly a Global Hawk and no service would accept that wing's risk in a manned plane.

Fascinating!

Quoting Faro (Reply 19):
Great development but what I don't understand is why this is all happening now.

If we are talking about shaping and surface finish only, and no active laminar flow systems, what critical technology is enabling these latest significant gains in the extent of laminar flow? Computational aids or manufacturing innovations or what exactly?

I don't know why now, but indeed my reading is that this does not have active controls involved, it's all about "natural laminar flow" via the shape and surface finish.

One recent reference is http://www.gkn.com/aerospace/media/n...tive-Clean-Sky-wing-structure.aspx which says:

Quote:

“The key challenge with designing and manufacturing an NLF wing, with the many aerodynamic benefits that promises, stems from the need to tightly control the wing surface. It is vital to eliminate features such as steps, gaps, surface roughness and waviness or fastener heads as these all lead to more traditional ‘turbulent flow’ performance levels. The GKN Aerospace team has created these integrated, co-cured composite upper covers and very high tolerance leading edge surfaces using the same structured design and development process applied in commercial aircraft programmes. As a result, our first part was of very high quality and has been delivered for the flight test programme - which for such an innovative structure was a huge achievement for the entire team.”

Implied in all of this is being able to do this at a commercial scale.

http://aviationweek.com/technology/e...ar-flow-demo-enters-assembly-phase (paywall) goes into a lot more things, such as the reason they use the A340 is because if they used a smaller a/c they would need to recertify the entire a/c before they could fly it, they will replace the existing panels starting at wing rib 27, Saab's design will be on one wing whereas GKN's will be on the other, and that everyone involved seems to have misjudged the amount of work involved in getting permits, implementing the designs and installing the extraordinary amount of instrumentation and sensors needed to document the results.

One fair-use paragraph gives the details of the manufacturing requirements:

Quote:

To provide the geometric and surface quality required for laminar flow, assembly tooling tolerance is ±0.04 mm. Rivet height is reduced to ±0.04 mm from ±0.1 mm for a conventional wing, an acceptable step to +0.07/-0.26 mm from ±0.5mm, aerodynamic accuracy to 0.8 mm from 1.5 mm, and surface waviness to 0.3 mm from 1 mm over a 100 mm length.

Seems to be very difficult, and seems it'll be hard to keep such uniformity throughout the life of the aircraft.
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Sat Jun 04, 2016 8:09 am

Quoting Revelation (Reply 20):

Quoting lightsaber (Reply 16):
Take the Global Hawk, it has normal bottom -side laminar and about two thirds top-side. When the Global Hawk stalks, it will spin and crash. Stall recovery is incredibly difficult and flight control soft spends an incredible amount of time avoiding stalling. No human pilot could fly a Global Hawk and no service would accept that wing's risk in a manned plane.

Fascinating!

Indeed! So the Global Hawk is maybe the first implementation of a marginally flyable wing. But this doesn't bode well for a commercial laminar wing's certification process...that will be tricky...

Quoting Revelation (Reply 20):
One fair-use paragraph gives the details of the manufacturing requirements:

Quote:

To provide the geometric and surface quality required for laminar flow, assembly tooling tolerance is ±0.04 mm. Rivet height is reduced to ±0.04 mm from ±0.1 mm for a conventional wing, an acceptable step to +0.07/-0.26 mm from ±0.5mm, aerodynamic accuracy to 0.8 mm from 1.5 mm, and surface waviness to 0.3 mm from 1 mm over a 100 mm length.

Seems to be very difficult, and seems it'll be hard to keep such uniformity throughout the life of the aircraft.

This looks to be a Herculean task.

First there is thermal expansion/contraction of the wingspan. IIRC in a past thread it was estimated that a 773 is something like 15cm longer going from -20°C to +40°C. Any accompanying wing surface distortion may degrade laminar flow.

Then particulate matter pollution which may dot an otherwise smooth wing surface with tiny dust/smoke/etc particles.

And finally long-term oxidation of the wing surface which may also have a roughening effect.

Coatings treatments like Diamond-Like Carbon exist to limit surface roughening, but they can't treat the surface distortion issue.


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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Sat Jun 04, 2016 10:26 am

Quoting Revelation (Reply 15):
What tooling would that be?

The A340-NG related tooling that now will be needed for the A340-NG-NG Laminar Edition that will clamored for in countless a.net posts, once this news becomes more widely circulated. 4-Engines-4-Longhaul-4-Ever!

This bird is a A340-300 produced on the same line as the A330 is produced today, using the same fuselage as the A330-300 and practically the same wing as the A330MRTT. I would say the tooling is well preserved.
 
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Sat Jun 04, 2016 5:55 pm

Quoting Revelation (Reply 15):
The A340-NG related tooling t

Afaik the A340NG wings were build up on a "flexible/universal CNC tool" .
See:
http://www.kinematics.com/media/Gera...pt?phpMyAdmin=69ec4ae0b5ddtf17d599
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Mon Jun 06, 2016 4:35 am

Quoting hivue (Reply 17):
I am guessing the stall speed and severity is elevated because the airflow over the wing is more "perfect" or "ideal," and so when the airflow finally breaks down at a high enough AoA and the wing stalls it's that much nastier.

Exactly. A stall will spread across the entire laminar flow surface very quickly (a high fraction of the speed of sound). Turbulent flow re-attaches a stall back to the wing. If there is a stall, the turbulence is not in the form the wing wants to maintain, so recovery happens when the wing resumes its normal turbulence.

Stall is *much* nastier on the underside. A wing drops very quickly with underside stall. Hence, why underside laminar flow has only been enabled where it was benign (unlikely to stall or the turbulence created likely to recover quickly).

This is *much* of airfoil selection. A very non-trivial part. It is why laminar flow is avoided in certain parts of the wing.

Quoting Faro (Reply 19):
what critical technology is enabling these latest significant gains in the extent of laminar flow? Computational aids or manufacturing innovations or what exactly?

New CFD and flight test understanding of how to stop the spread of a stall.

I wish I could go more into the detail, but I would be violating an NDA discussing more than is commonly known.

Mostly it was $100+/bbl oil forcing airframers to dust off old R&D and look into implementing it. Inertia in this industry is painful. It is almost easier for me to discuss the few new technologies I've worked in my carrier than the horde of old technologies we finally understand the risk well enough.

But part was a *far better understanding* due to one UAV having a control surface fail during a laminar flow wing test flight. The neat thing about UAVs are their high endurance and this one had a different chip that enabled software loads *in flight*. (Very rare for that to be enabled, due to security and safety concerns.) CFD showed possible solution (done incredibly quickly, during a flight) and a new software build was created and *bare minimum* tested and uploaded. That one instance opened up a whole new understanding of laminar flow wings. For a plane that wobbled at 150% of landing speed too dangerously to land, a new build enabled a safe landing.

It changed an industry (well... expensive oil added the incentive). Because of that one success, a whole bunch of other 'solutions' were flight tested. An 'analysis matrix' for failed components was understood and belief in the CFD software to predict stall and recovery.

No tech changed (not really), just a belief in that it would work and high enough oil prices to drive.

There is a reason laminar flow around nacelles and innocuous regions of the plane were done first.

For those who want to know more, first study the 'drag crisis:'
https://www.grc.nasa.gov/www/k-12/airplane/dragsphere.html

It is the seperation of flow that is 'stall.' That must be avoided. Laminar flow wings risk that, but how to avoid is now much better understood. And yea, that link shows the effect of the drag crisis, but does not fully describe it. It took me a month of grad school studying fluids to wrap my mind around all the angles... assuming a perfect sphere.  
Quoting Faro (Reply 21):
First there is thermal expansion/contraction of the wingspan. IIRC in a past thread it was estimated that a 773 is something like 15cm longer going from -20°C to +40°C. Any accompanying wing surface distortion may degrade laminar flow.

Then particulate matter pollution which may dot an otherwise smooth wing surface with tiny dust/smoke/etc particles.

And finally long-term oxidation of the wing surface which may also have a roughening effect.

Less oxidization than dings (hail), bird poop, and other instances.

But yes, all the solutions must work for all manufacturing tolerances, all in flight wing flex and lift deflection, all thermal growth/contraction, and most of all be safe at low air speeds where laminar flow wings have the most issues.

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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Mon Jun 06, 2016 9:49 am

Quoting hivue (Reply 9):
"The North American P-51 Mustang was the first aircraft intentionally designed to use laminar flow airfoils."

Going off at a bit of a tangent (and acknowledging the obvious "not all laminar wings are born equally")...


I have been told (many moons ago) that the suction surfaces of the Su-27 and MiG-29 are rough. Dog rough. Intentionally so as to keep the boundary layer behaving at a slightly higher AoA than otherwise.

The story goes that the "western capitalist dogs" (thats us in NATO - or OTAN if eat frogs legs) were very surprised at this when they first got a look at the Flanker in Paris in '89.


[Of course, this could be a load of crap, and the fella that told me was full of it...]

[Edited 2016-06-06 02:49:43]
 
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Mon Jun 06, 2016 10:10 am

Quoting lightsaber (Reply 24):
But part was a *far better understanding* due to one UAV having a control surface fail during a laminar flow wing test flight. The neat thing about UAVs are their high endurance and this one had a different chip that enabled software loads *in flight*. (Very rare for that to be enabled, due to security and safety concerns.) CFD showed possible solution (done incredibly quickly, during a flight) and a new software build was created and *bare minimum* tested and uploaded. That one instance opened up a whole new understanding of laminar flow wings. For a plane that wobbled at 150% of landing speed too dangerously to land, a new build enabled a safe landing.

It changed an industry (well... expensive oil added the incentive). Because of that one success, a whole bunch of other 'solutions' were flight tested. An 'analysis matrix' for failed components was understood and belief in the CFD software to predict stall and recovery.

Wow...speechless.

This is indeed a revolution, like area-ruling, supercritical wings and turbofans. Amazing that it remains to this day so low-profile. Thanx a million Lightsaber!


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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Mon Jun 06, 2016 3:49 pm

Quoting Faro (Reply 21):
Then particulate matter pollution which may dot an otherwise smooth wing surface with tiny dust/smoke/etc particles.
Quoting lightsaber (Reply 24):
Less oxidization than dings (hail), bird poop, and other instances.

It's interesting how the leading edges of the test sections on the A340 will have a "blow-away" paper covering that, I guess, can be commanded (yanking on a string or something) to depart the airplane after it's in the air and away from potential ground FOD.
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Tue Jun 07, 2016 2:28 am

Quoting hivue (Reply 27):
It's interesting how the leading edges of the test sections on the A340 will have a "blow-away" paper covering that, I guess, can be commanded (yanking on a string or something) to depart the airplane after it's in the air and away from potential ground FOD.

Since we've had the winglet then the sharklet perhaps this should be called the prophylaclet? 
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Tue Jun 07, 2016 5:05 am

M=0.75 is pretty slow by modern airplane standards. I wonder if they can

Quoting Faro (Reply 21):

This looks to be a Herculean task.

That's my impression, which is that this wing is utterly impractical for any sort of commercial or military use. So what's the big picture? Why are they doing this? I get they can save 5-15% fuel, but that's not an enormous step change.
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Tue Jun 07, 2016 8:27 am

Quoting lightsaber (Reply 24):
New CFD and flight test understanding of how to stop the spread of a stall.

I wish I could go more into the detail, but I would be violating an NDA discussing more than is commonly known.

So it seems that Airbus has been on to this proprietary technology and have duplicated it somehow? I would think there was some kind of patent protection...perhaps they purchased licence rights?


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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Tue Jun 07, 2016 9:32 am

Maybe using acoustic flow excitation to burst the separation bubble by kind of injecting turbulent flow into the wing when its about to stall.

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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Tue Jun 07, 2016 11:57 am

Quoting DocLightning (Reply 29):
I get they can save 5-15% fuel, but that's not an enormous step change.

It isn't? Winglets got 4-5% and it seems the entire industry has spend billions switching over.

I too wonder about the sustainability, but that doesn't mean you shouldn't research the heck out of the available concepts.

It may turn out to be impractical in practice, or maybe you only see some of the gain in a sustainable mode, but it's still worth knowing more about it.

And in any case it seems this testbed will have some value over an extended period testing various airfoil ideas in the real world.
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Amiga500
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Tue Jun 07, 2016 12:07 pm

Quoting Faro (Reply 30):
So it seems that Airbus has been on to this proprietary technology and have duplicated it somehow? I would think there was some kind of patent protection...perhaps they purchased licence rights?

Faro

Eh? How do you patent aerofoil design?


You can patent a particular aerofoil section*. But I don't think your going to be able to patent a range of variations around it.


*for example; http://m-selig.ae.illinois.edu/ads/coord_database.html
 
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KarelXWB
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Tue Jun 07, 2016 12:28 pm

Quoting DocLightning (Reply 29):
I get they can save 5-15% fuel, but that's not an enormous step change.

Every 1% fuel burn cut is worth going for; 5 to 15% is huge. Combine that with a new engine and you have an airplane that burns a significant amount less fuel.
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Tue Jun 07, 2016 3:39 pm

Quoting Amiga500 (Reply 33):

They are not developing a 2D section it's a 3D wing.
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Tue Jun 07, 2016 10:29 pm

Quoting Revelation (Reply 32):

It isn't? Winglets got 4-5% and it seems the entire industry has spend billions switching over.

But winglets are not a herculean task that put the entire aircraft at risk of stall, stop working if there's a bug on them, and require a M=0.1 decrease in flight speed.

It seems to me that the practicalities here are such that the benefit will be really much smaller than advertised.
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Wed Jun 08, 2016 1:21 am

Quoting DocLightning (Reply 36):
It seems to me that the practicalities here are such that the benefit will be really much smaller than advertised.

But of course the best way to understand the "practicalities" better is to start flying these kinds of testbeds around. You may learn some parts of the problem aren't as bad as you thought, you may find others are worse, you may find problems you didn't know about (probably will!) and you may find benefits you didn't count on.

Only so much can be done in a wind tunnel or in a computer simulation.

And you may learn things that will never be used on an airliner but might be used on a UAV. You might learn things about manufacturing to high tolerances that might not produce natural laminar flow but might help improve more traditional wings.

It sounds like they've already learned a lot about instrumenting this kind of testbed and what it takes to get it certified for flight.
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Wed Jun 08, 2016 8:24 am

Quoting Amiga500 (Reply 33):
Eh? How do you patent aerofoil design?
Quoting Amiga500 (Reply 33):
You can patent a particular aerofoil section*
Quoting zeke (Reply 35):
They are not developing a 2D section it's a 3D wing.

From my work on IP the only limitation on getting a patent is that it's new and novel, if you can prove those things then you can patent it.

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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Wed Jun 08, 2016 9:10 am

Quoting flipdewaf (Reply 38):

Quoting Amiga500 (Reply 33):
Eh? How do you patent aerofoil design?
Quoting Amiga500 (Reply 33):
You can patent a particular aerofoil section*
Quoting zeke (Reply 35):
They are not developing a II Airways (Italy)">2D section it's a 3D wing.

From my work on IP the only limitation on getting a patent is that it's new and novel, if you can prove those things then you can patent it.

Fred

Yes but if Airbus's testing is based on a laminar flow innovation which is new and novel, then we have two revolutionary new innovations in wing design, don't we? Laminar Flow I stemming from the Global Hawk and Laminar Flow II coming from Airbus...seems a tad to much to me...


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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Wed Jun 08, 2016 9:59 am

Quoting Faro (Reply 39):

Yes but if Airbus's testing is based on a laminar flow innovation which is new and novel, then we have two revolutionary new innovations in wing design, don't we? Laminar Flow I stemming from the Global Hawk and Laminar Flow II coming from Airbus...seems a tad to much to me...

So if there is 2 different ways to achieve the laminar flow and they are both new and novel then they can both be patented as separate things.
If device A uses research X to create laminar flow then device B can use research X to create laminar flow also and still be patented.

If device A uses research X to create laminar flow and device B uses research Y to create Laminar flow but the device B is not sufficiently new and novel compared to device A then it cannot be patented.

Patents are based around what an idea is and not what it does.

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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Wed Jun 08, 2016 12:05 pm

Quoting zeke (Reply 35):
They are not developing a 2D section it's a 3D wing.

Which is a series of aligned aerofoil sections.

If your point is that adding the 3d dimension greatly complicates any attempts to patent a "design" that can exclude competitors from developing something very similar then yes, agree 100%.
 
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Wed Jun 08, 2016 12:10 pm

Quoting flipdewaf (Reply 38):
From my work on IP the only limitation on getting a patent is that it's new and novel, if you can prove those things then you can patent it.

Fred

You can't exactly word a patent like:

"we patent an aerofoil design that doesn't transition from laminar to turbulent flow till at least 50% chord length on pressure and suction surface".

That doesn't work*. That doesn't describe a design, its just a broad idea.


Your going to have to describe it geometrically to nail it down, as is the case with **all** previous aerofoil patents (that I know of - its a little different in turbines etc, but thats not applicable here). At that point a competitor just has to vary it slightly (which they will do anyway due to 3D effects) and hey presto, not covered by the patent and they have the same (or better) result.



*well, it might in the US patent office where brains doesn't apply. But would be chucked out in courts.
 
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Wed Jun 08, 2016 12:30 pm

Quoting Amiga500 (Reply 42):

You can't exactly word a patent like:

"we patent an aerofoil design that doesn't transition from laminar to turbulent flow till at least 50% chord length on pressure and suction surface".

You can describe how it works in the description part of the patent application, but what it DOES it not what is patented, the patented part is what it IS. For the avoidance of doubt I think we are agreeing with each other.

Quoting Amiga500 (Reply 42):
Your going to have to describe it geometrically to nail it down, as is the case with **all** previous aerofoil patents (that I know of - its a little different in turbines etc, but thats not applicable here). At that point a competitor just has to vary it slightly (which they will do anyway due to 3D effects) and hey presto, not covered by the patent and they have the same (or better) result.

This is where patents become difficult, you can have a calim which says " the airofoil has a geometry of XYZ and a span of X meters"
"the airofoil of the previous claim with span of not less than X meters and up to X + Y meters" so that a range of geometries can be encompassed.
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Amiga500
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Wed Jun 08, 2016 12:59 pm

Quoting flipdewaf (Reply 43):
This is where patents become difficult, you can have a calim which says " the airofoil has a geometry of XYZ and a span of X meters"
"the airofoil of the previous claim with span of not less than X meters and up to X + Y meters" so that a range of geometries can be encompassed.

I think this is where zeke was driving at earlier - modern wings are never really constant section, so trying to make it general enough to preclude others from doing similar would be extremely difficult, if not practically impossible.
 
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RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Thu Jun 09, 2016 12:58 am

Quoting DocLightning (Reply 29):
So what's the big picture? Why are they doing this? I get they can save 5-15% fuel, but that's not an enormous step change.

Going by that, the 787 too doesn't bring an enormous step change in fuel efficiency for most of the missions then. The A330neo is likely to come within single digits of the 787 in fuel burn just by hanging the same new generation engines.
 
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Re: RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Wed Jun 22, 2016 11:22 am

Faro wrote:
So it seems that Airbus has been on to this proprietary technology and have duplicated it somehow? I would think there was some kind of patent protection...perhaps they purchased licence rights?

Every airframer has patent rights on laminar flow wings. What changes is how to keep stalls from propagating through the laminar flow region (turbulent regions are inherently stall resistant).

Much of the technology is owned by NASA and was put into the public domain; the idea being that cutting greenhouse emissions benefits the US taxpayers that funded the R&D. Airbus has also participated in government funded R&D on laminar flow. Some is that the original techniques to control laminar flow date from the WW2 Mustang/King Cobra and the patents are *long* expired. Another issue is in the 1980s there was a burst in the technology, but certain aspects were not ready, so the bulk of the patents are expired.

This is a slow industry. Any patent prior to 1996 is now expired. I've spent a career implementing expired patents. Very few of the concepts I have personally engineered into aircraft or engines weren't at least 25 years old with some final idea to make it happen.

Some of the growth is new CFRP techniques. It is *much* easier to make a CFRP laminar wing than aluminum with its rivits. This includes having much more 3D shapes to the wing instead of stretched 2D cross sections.

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Re: RE: Airbus Laminar Flow Demonstrator To Fly In 2017

Wed Jun 22, 2016 5:21 pm

lightsaber wrote:
Any patent prior to 1996 is now expired. I've spent a career implementing expired patents. Very few of the concepts I have personally engineered into aircraft or engines weren't at least 25 years old with some final idea to make it happen.

And most corporate entities strongly encourage patenting any plausible "final idea" so that they can control it for as long as possible...
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Re: Airbus Laminar Flow Demonstrator To Fly In 2017

Sun Jun 26, 2016 9:35 am

Isn't it a bit navel centric to assume that all relevant information and research was solely done in the US and
all others have to steal or at least borrow?

The British handed over a lot of research during WWII and the rather large "infusion" of German knowledge came via Operation Paperclip.( Made the day for Boeing at the time )

Don't assume that neither made any progress later on.
Soviet Union/Russia is also a fount of in depth theoretical/analytical and practical knowledge.
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Re: Airbus Laminar Flow Demonstrator To Fly In 2017

Sun Jun 26, 2016 10:32 am

WIederling wrote:
Isn't it a bit navel centric to assume that all relevant information and research was solely done in the US and all others have to steal or at least borrow?

I don't think that assumption is being made. Lightsaber has said in the past that a lot of the things he implemented came from expired Rolls patents.
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