LY777
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B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 3:59 am

Direct from Boeing website:

SEATTLE, July 10, 2006 -- The Boeing [NYSE: BA] 787 program has made a subtle but important change to the airplane's livery to enhance airplane performance. By developing a method for maintaining a smooth flow of air -- called laminar flow -- over more area on the 787 nacelle inlet, Boeing is able to reduce aircraft drag and fuel consumption.

The 787 nacelle has a tightly controlled smooth surface to preserve laminar flow over a greater distance than that on a standard design. "Aircraft drag is reduced because laminar flow has much lower skin friction drag than turbulent flow," said Ron Hinderberger, propulsion leader for the 787 program.

To achieve laminar flow over the inlet it is necessary to maintain a very smooth, continuous surface without paint edges, which can occur when paint transitions from one color to another, or as paint details are added. The design parameter for the nacelles is based on thickness of the paint formulation for a single color; Boeing has chosen gray to complement the metallic appearance of the nacelle's inlet.

"If you interrupt the laminar flow by adding paint layers, which are common with airline liveries, you could increase fuel burn by 30,000 gallons per year per airplane," Hinderberger added. "An improvement like this -- especially with rising fuel prices -- can contribute positively to the bottom line for an airline."

[Edited 2006-07-10 21:00:44]
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AAgent
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 4:07 am

Quoting LY777 (Thread starter):
Boeing has chosen gray to complement the metallic appearance of the nacelle's inlet.

Well, that's a bit of a head start for AA when they decide to order the aircraft.

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AAgent
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NYC777
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 4:08 am

Quite interesting that Boeing is using gray around the inlet to sustain laminar flow around the inlet. I guess the airlines would rather save 30k gallons of fuel (and some paint) instead of have some livery around the engine inlets. I don't think they'll mind.
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ikramerica
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 4:09 am

Wow.

I would assume it could be any color, but that is must be applied in a special way. One can even assume that using a controlled spray you could do a gradient or something else.

It also sounds as if this isn't just a case of "you can apply it to any jet and save" as it has to do with the shape of the nacelles first, and then controlling the paint process not to disrupt flow over the tweaked nacelle.
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airmailer
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 5:00 am

hmmmmm.....

Makes me wonder how overweight the 787 is.
... just thinking that if they are looking at something as small as this (I mean how think is paint 1/100th of an inch), that the thing might be overweight afterall.

....On the other hand, maybe the 787 is underweight and this is just icing on the cake.

Time will tell.
 
DLSLC
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 5:07 am

Quoting LY777 (Thread starter):
"If you interrupt the laminar flow by adding paint layers, which are common with airline liveries, you could increase fuel burn by 30,000 gallons per year per airplane,"

Wow, I had no idea it could increase the fuel burn by 30K gallons per year, that is crazy.
My thought is that it is just icing on the cake, I think if it were overweight they would be more concerned about larger aspects of the aircraft that would put it overweight. Just my thought.
Devin B.
 
NYC777
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 5:11 am

Quoting AirMailer (Reply 4):
Makes me wonder how overweight the 787 is.
... just thinking that if they are looking at something as small as this (I mean how think is paint 1/100th of an inch), that the thing might be overweight afterall.

Well it not the weight of the paint that 's making a difference it is making sure that the air flow over the nacelle's are laminar and not turbulent. If it is turbulent then you create drag which increases fuel consumption. The grey paint will ensure that the air flow over the nacelles is laminar.
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MCIGuy
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 5:12 am

Quoting AirMailer (Reply 4):
hmmmmm.....

Makes me wonder how overweight the 787 is.
... just thinking that if they are looking at something as small as this (I mean how think is paint 1/100th of an inch), that the thing might be overweight afterall.

....On the other hand, maybe the 787 is underweight and this is just icing on the cake.

Time will tell.

Last check showed that the 787 is indeed around 1% over the target weight. Boeing is working to reduce the weight, but is also making aerodynamic and other improvements to offset it. This is not uncommon.
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gregarious119
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 5:29 am

Does a window weigh more or less than the fuselage it replaces?

If it's heavier, you'd think the oversize windows may be a problem.

If they are lighter, then howabout some oversize windows in Coach too???  Smile

Is the laminar flow affected on any other forward-facing surfaces such as the wing fronts or the vertical stabilizer?
 
MCIGuy
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 5:40 am

Quoting Gregarious119 (Reply 8):
Does a window weigh more or less than the fuselage it replaces?

If it's heavier, you'd think the oversize windows may be a problem.

If they are lighter, then howabout some oversize windows in Coach too???

Is the laminar flow affected on any other forward-facing surfaces such as the wing fronts or the vertical stabilizer?

Yes, glass is a very heavy material, comparatively. However the 787 will have the larger windows in all classes. 'Twould look funny from the outside to have multiple windows sizes on one frame, don't you think?  

[Edited 2006-07-10 22:41:19]

[Edited 2006-07-10 22:42:02]
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oly720man
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 5:45 am

Quoting NYC777 (Reply 6):
The grey paint will ensure that the air flow over the nacelles is laminar.

Any paint will do. It's the fact that there are no edges between paint colours that will reduce the problem. Hopefully the nacelles themselves won't have too many panels where the edges could cause the same problem.

Quoting DLSLC (Reply 5):
Wow, I had no idea it could increase the fuel burn by 30K gallons per year, that is crazy.

In terms of the total fuel usage it's not a lot. Let's say in simple terms a plane flies 300 days a year, that's 100 gallons a day, or 300kg in weight or thereabouts. Equivalent to a couple of pax. Or if there are 2 flights a day, 1 pax per flight, or the various bottles of duty free and other goodies the pax buy at the departure airport. This saving could quite easily be lost if the nacelles get dirty. So, does the airline spend the money to keep the plane clean or have a dirtier plane, and lose the small saving?

And added to that, there are other bigger fuel losses just taxying to the runway, stacking when flying to a big airport and taxying to the terminal at the other end.
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RichardPrice
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 5:48 am

How soon until we see liveries being applied directly into the top composite layer instead of over the layer using paint?

Should be interesting.
 
MCIGuy
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 5:52 am

Quoting RichardPrice (Reply 11):
How soon until we see liveries being applied directly into the top composite layer instead of over the layer using paint?

Should be interesting.

Wow, very coo RichardPrice, I never even thought of that, embedded liveries. Would make it beach when they want to change liveries though, wouldn't it?
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baron95
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 5:54 am

Quoting LY777 (Thread starter):
necessary to maintain a very smooth, continuous surface without paint edges, which can occur when paint transitions from one color to another

This is the basic issue of natural laminar flow around surfaces - it is very susceptible to contamination (e.g. rain), dirt/dust, scratches, paint chips, and even in extreme cases paint thinkness variation.

I wonder if this will turn into a maintenance nightmare where minor dirt, scratches, paint touch-ups end up costing a few thousand gallons of fuel/year. This reminds me about the care needed by the B2 and F22 to maintain stealth - if you scratch one during maintenance they'll dock 2 years of your salary  Smile
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grantcv
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 7:30 am

Hmmm, I wonder if there would be benefit from applying the same logic to the entire fuselage. By controlling the laminar flow over the nose by painting the fuselage a single uniform gray color, maybe they could improve the efficiency even more. And if they leave off all fuselage decals, then the entire surface of the plane could be very smooth except for the windows. Maybe if they left out cabin windows they would save the weight and complexity of having windows altogether and the laminar flow would be better - a double savings.
 
firennice
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 7:55 am

Quoting MCIGuy (Reply 12):
Wow, very coo RichardPrice, I never even thought of that, embedded liveries. Would make it beach when they want to change liveries though, wouldn't it?

Throw it away and get a new one.....or paint the entire thing over.
 
F14ATomcat
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 9:31 am

I guess the interesting thing here is 30,000 gallons per year = 577 gallons per week.... Say six long flights per week = apprx 100 gallons per flight and @ $2.00 per gallon = $200 per flight. It's something.... But by itself not worth writing home to mom about.
 
ikramerica
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 9:44 am

Assume average usage of 6 days out of 7 per week (which allows for checks and such throughout the year). The average 787 will make 2 flights a day, or 12 flights a week or 625 or so a year. That's really only 48 gallons a flight or $100 a flight, or on a 788, $0.50 cents per pax.

So, is a distinctive engine livery worth $0.50 per pax? Only an airline would know for sure, but considering the lengths an airline will go through to save a few cents per pax on other things (pillows, pretzels, etc.)...
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centrair
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 9:56 am

Quoting RichardPrice (Reply 11):
How soon until we see liveries being applied directly into the top composite layer instead of over the layer using paint?

Should be interesting.

The paint is baked on isn't it? If a 787 is leased, that means it could be used at many different airlines over its life. So how do you repaint a 787?
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glennstewart
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 10:10 am

Quoting MCIGuy (Reply 7):
Last check showed that the 787 is indeed around 1% over the target weight.

Boeing should take a leaf from Mazda's book.
Although an airliners and a sports car can't be compared, I found Mazda's focus on weight saving in their new MX-5, was an amazing feat.

The main key of designing the MX-5 was to ensure it was recognisable as being an MX-5 and had the same sports car performance. Unfortunately, with the addition of many new safety features (required in some countries by law), the weight was bound to increase.

The Mazda engineers were told to review every single part in the car. When they revealed the vehicle, they made an example of the side mirrors - where they were able to save 84 grams on just that piece.

Over the whole car, they saved enough to compensate for 250kg of extra safety equipment - with an overall increase of a mere 50kg over the previous model.

The convertible hardtop version was recently unveiled in the UK. Car mags around the world were assuming two things:

1. Too much extra weight
2. Too much space taken up in boot/trunk

Mazda released the hardtop noting that the entire hardtop section weighed a tiny 30kg, and it folded in such a way, that it took up no extra room in boot.

Amazing engineering!!!


Glenn
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boeingbus
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 10:56 am

Check it out...

Big version: Width: 450 Height: 300 File size: 15kb


Why gray? wish it was white...
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DfwRevolution
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 11:15 am

Quoting Centrair (Reply 18):

The paint is baked on isn't it? If a 787 is leased, that means it could be used at many different airlines over its life. So how do you repaint a 787?

No, the 787 fuselage emerges from the autoclave appearing a charcole color. This is coated with a primer, and then the airline colors.

Paint removal is likely simmilar to that of a conventional aircraft, with attention to solvents and abrasives that won't compromise the CFRP. Notice the interior, unpainted section of this fuselage barrel, and this unpainted nose section -



 
ikramerica
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 11:16 am

They chose grey for the livery. White will probably look too dirty in all the photos they will take over the time of the testing. And in sunlight, grey will look pretty white.

But any airline can choose any livery they want. To take advantage of the tweak, they would just need a single color, no decals or patterns.
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chrisnh
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 12:19 pm

so much for a Wanula  spin  Dreaming 787, I guess
 
AAgent
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 12:26 pm

Quoting BoeingBus (Reply 20):
Why gray?

Perhaps Boeing is fishing for an aircraft order from AA. They've painted the nacels the right color. Now if Boeing would just offer a shiny polished aluminum skin appearance package for the fuselage, a 787 order from AA would be greatly encouraged.

Best Regards,
AAgent
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zamaria
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 12:36 pm

This seems like a good idea.

On a related fuel-saving idea note, anybody know what happened to the idea that I thought Boeing was testing regarding attaching an electric motor to the nose-wheel for taxi use instead of having to use the engines? That also seemed like a great idea, though perhaps the added weight of the "taxi-motor" offsets the fuel savings of not having to use the engines while taxiing?

-Z
 
WingedMigrator
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 12:38 pm

Quoting NYC777 (Reply 6):
The grey paint will ensure that the air flow over the nacelles is laminar.

What a brilliant idea! Sounds like something that could be applied to the tail as well!  Big grin

More seriously, how can this possibly matter compared to cowling seams? Would those not trip the boundary layer much more easily than the edge of a paint layer?
 
centrair
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 12:40 pm

Thank you DFWrevolution. I get it now.

So this grey doesn't effect the frame but the engines only?

So if I understand this, an airline can choose any color for the engine nacelle but might take a very small penalty if the color is complex or has layers? Grey gives the shiney effect, but could an airline do all white, all black, or all blue?
Yes...I am not a KIX fan. Let's Japanese Aviation!
 
DfwRevolution
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 1:06 pm

Quoting Centrair (Reply 27):
So if I understand this, an airline can choose any color for the engine nacelle but might take a very small penalty if the color is complex or has layers?

Right: Any solid color will have a slight aerodynamic advantage over an engine nacelle with decals or paintlines.

Boeing has simply chosen a grey shade because they think it will complement the other colors on the aircraft in its' Dreamliner scheme.
 
Grbld
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 3:47 pm

For those that think a $200 savings per flight or $0.50 per passenger savings per flight is peanuts, consider this:

The airline I work for carried 5 million passengers last year and made about 13 million dollars in profit. This comes down to about $ 2.50 per passenger. So if you save an extra $ 0.50 per passenger, you've just increased your profit per passenger by 20%. And this result is pretty good, I remember when we were making just $ 0.50 profit per passenger. In this case, you'd have doubled your profits!

Right now we've got new winglets installed on all our aircraft, saving about 3-4% of fuel. These babies cost more than half a million euros per plane to install yet on an average stretch where you burn 6000 liters, you may save 180-240 liters. And that's after spending all that cash to install them in the first place!

So in the grand scheme of things, these "tiny" numbers may seem insignificant, but I assure you, they are not!

Luckily I'm flying for a company that actually makes a profit, you can imagine the above comparison for an airline that makes a loss.


Grbld.
 
Gary2880
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 4:43 pm

Quoting Baron95 (Reply 13):
This reminds me about the care needed by the B2 and F22 to maintain stealth - if you scratch one during maintenance they'll dock 2 years of your salary

your joking??? god help the pilot if he clatters one in to a bird.

as for painting this 787, why not paint it as normal, then dip it in a nice coat of varnish to make it smooth? Big grin
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Molykote
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 5:44 pm

Quoting Glennstewart (Reply 19):
The main key of designing the MX-5 was to ensure it was recognisable as being an MX-5 and had the same sports car performance. Unfortunately, with the addition of many new safety features (required in some countries by law), the weight was bound to increase.

The Mazda engineers were told to review every single part in the car. When they revealed the vehicle, they made an example of the side mirrors - where they were able to save 84 grams on just that piece.

Over the whole car, they saved enough to compensate for 250kg of extra safety equipment - with an overall increase of a mere 50kg over the previous model.

I own an MX-5 and I've personally handled hundreds of the components of an MX-5.

I don't see how 550lb of "extra" safety equipment made its way into the third generation model (It's a 2500lb car). Even counting bumper covers, the underlying bumper structure, etc, I can't see 550lb (especially as you were talking about "extra" equipment - this stuff all would have been common to the old car).

I personally think that the MX-5 is one of the best executed concepts on the market but I can't begin to imagine where the 250Kg comes from.
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MCIGuy
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 6:04 pm

Quoting Grantcv (Reply 14):
I wonder if this will turn into a maintenance nightmare where minor dirt, scratches, paint touch-ups end up costing a few thousand gallons of fuel/year. This reminds me about the care needed by the B2 and F22 to maintain stealth - if you scratch one during maintenance they'll dock 2 years of your salary

Well yeah, it can make a difference in the RCS of the frames you mentioned, but maintenence fubars will happen.  
I think what they're saying at Boeing is that they're being such freaks about aerodynamic efficiency on the 787 project that they actually caught this. It's probably always been true, but they just now discovered it.

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[Edited 2006-07-11 11:09:12]
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vzlet
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 10:15 pm

All of these queries/points...

Quoting BoeingBus (Reply 20):
Why gray? wish it was white...



Quoting Ikramerica (Reply 22):
They chose grey for the livery. White will probably look too dirty in all the photos they will take over the time of the testing. And in sunlight, grey will look pretty white.



Quoting AAgent (Reply 24):
Quoting BoeingBus (Reply 20):
Why gray?

Perhaps Boeing is fishing for an aircraft order from AA. They've painted the nacels the right color. Now if Boeing would just offer a shiny polished aluminum skin appearance package for the fuselage, a 787 order from AA would be greatly encouraged.



Quoting DfwRevolution (Reply 28):
Boeing has simply chosen a grey shade because they think it will complement the other colors on the aircraft in its' Dreamliner scheme.

...were addressed in the initial post:

Quoting LY777 (Thread starter):
Boeing has chosen gray to complement the metallic appearance of the nacelle's inlet.
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DfwRevolution
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 10:18 pm

Quoting Vzlet (Reply 33):
...were addressed in the initial post:

Yeah I was clarifying it for someone who asked.

Way to waste text and be a tool...  Yeah sure
 
DAYflyer
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 10:39 pm

Talk about fine tweaking an airplane before roll out, wow.
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roseflyer
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RE: B787 Livery Change Enhances Airplane Performance

Tue Jul 11, 2006 11:16 pm

Quoting AirMailer (Reply 4):
Makes me wonder how overweight the 787 is.
... just thinking that if they are looking at something as small as this (I mean how think is paint 1/100th of an inch), that the thing might be overweight afterall

All improvements are good. Making a blanket statement like your assumption is ridiculous. I work in producibility at the moment and spend much of my time looking to improve things in subtle ways that will cut costs while making sure efficiency is maintained. I'm working on something to cut costs for the 787 at the moment. The goal is to make the most money possible, so if there can be savings found somewhere, then they will be exploited if it is cost effective to go through the work of finding them. Designs are constantly refined. Why stop at 20% improvements when you can go further? A good company will constantly be looking to improve its designs.

Quoting Baron95 (Reply 13):
This is the basic issue of natural laminar flow around surfaces - it is very susceptible to contamination (e.g. rain), dirt/dust, scratches, paint chips, and even in extreme cases paint thinkness variation.

I think this is a bigger concern. There is definitely a significant difference in drag between laminar and turbulent, but things want to go turbulent. I'm sure a brand new clean plane will see a difference between paint thicknesses as they influence laminar and turbulent, but I can't imagine that they can keep the surface uncontaminated to the point where the same effect lasts for the life of the plane. I think the end result is that a change like this will help get the plane the initial fuel efficiency figures that the airlines want.
If you have never designed an airplane part before, let the real designers do the work!
 
DfwRevolution
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RE: B787 Livery Change Enhances Airplane Performance

Wed Jul 12, 2006 1:04 am

Quoting Centrair (Reply 27):
So if I understand this, an airline can choose any color for the engine nacelle but might take a very small penalty if the color is complex or has layers? Grey gives the shiney effect, but could an airline do all white, all black, or all blue?

Having just read a Flight International article on this topic, it would appear to conflict with what I assumed from the Boeing press relase:

Quoting DfwRevolution (Reply 28):
Right: Any solid color will have a slight aerodynamic advantage over an engine nacelle with decals or paintlines.

Boeing has simply chosen a grey shade because they think it will complement the other colors on the aircraft in its' Dreamliner scheme.

According to Flight, a very specific thickness of the paint is required to establish laminar flow. To qoute the article:

"Boeing plans to reduce airframe drag on the 787 by standardising on a specific thickness of grey paint (pictured below) for the engine inlet which it says will preserve natural laminar flow over a larger area."

So maybe grey is the only shade being offered that will meet the application guidelines for laminar flow?

http://www.flightglobal.com/Articles...or+787s+in+bid+to+reduce+fuel.html
 
scouseflyer
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RE: B787 Livery Change Enhances Airplane Performance

Wed Jul 12, 2006 1:11 am

Quoting RichardPrice (Reply 11):
How soon until we see liveries being applied directly into the top composite layer instead of over the layer using paint?

Should be interesting.

They could get around all of this by making the skin out of my patented Chameleon Carbon Fibre that can display anything required - livery, adverts, worldcup matches and make itself look like the runway when the plane goes into stealth mode - no more repainting!!!!
 Big grin
 
roseflyer
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RE: B787 Livery Change Enhances Airplane Performance

Wed Jul 12, 2006 6:57 am

Quoting Scouseflyer (Reply 38):
They could get around all of this by making the skin out of my patented Chameleon Carbon Fibre that can display anything required - livery, adverts, worldcup matches and make itself look like the runway when the plane goes into stealth mode - no more repainting!!!!

Well carbon fiber itself is somewhat transparent. So all you need is a good matrix material, and boom, free advertising on the side of a plane!

Quoting DfwRevolution (Reply 37):
Boeing plans to reduce airframe drag on the 787 by standardising on a specific thickness of grey paint (pictured below) for the engine inlet which it says will preserve natural laminar flow over a larger area."

So maybe grey is the only shade being offered that will meet the application guidelines for laminar flow

That doesn't make a whole lot of sense to me. I know the equations for skin friction are messy. It is so incredibly difficult to find out where the exact turbulent to laminar transition is analytically. You end up with a mess of equations that aren't solveable (for example the henderson-hasselbach equation that is not solveable analytically and numerical methods have to be used since it is based on experimental data). Overall I don't think the color of paint factors in.
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FriendlySkies
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RE: B787 Livery Change Enhances Airplane Performance

Wed Jul 12, 2006 6:59 am

I doubt only grey paint can be used...I mean, is blue paint chemically "thicker" than grey?
 
willyj
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RE: B787 Livery Change Enhances Airplane Performance

Wed Jul 12, 2006 8:53 am

Quoting Ikramerica (Reply 17):
So, is a distinctive engine livery worth $0.50 per pax? Only an airline would know for sure, but considering the lengths an airline will go through to save a few cents per pax on other things (pillows, pretzels, etc.)...

or you could look at it as $60,000 per plane per year...
 
ikramerica
Posts: 13730
Joined: Mon May 23, 2005 9:33 am

RE: B787 Livery Change Enhances Airplane Performance

Wed Jul 12, 2006 8:55 am

Quoting Willyj (Reply 41):
or you could look at it as $60,000 per plane per year...

But it all comes down to pax flown, not planes.

Planes sitting still do nothing. Only when they fly pax do they achieve anything. So costs are thought of on a per pax basis.
Of all the things to worry about... the Wookie has no pants.
 
jacobin777
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RE: B787 Livery Change Enhances Airplane Performance

Wed Jul 12, 2006 9:06 am

Quoting RoseFlyer (Reply 39):
henderson-hasselbach equation

actually the henderson-hasselbach equation is quite straightforward, especially in the presence of a strong buffer.. biggrin 
"Up the Irons!"
 
roseflyer
Posts: 9606
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RE: B787 Livery Change Enhances Airplane Performance

Wed Jul 12, 2006 10:43 am

Quoting Jacobin777 (Reply 43):
actually the henderson-hasselbach equation is quite straightforward, especially in the presence of a strong buffer..

Sorry I'm an idiot. I should have paid more attention in college classes. I was talking about the Haaland equation, which lets you determine the roughness of a surface. For those of you curious what I'm talking about, this is the equation that somehow they solved for gray paint:

1/sqrt(f)=-1.8log([((e/D)/3.7)^1.11+6.9/R]
If you have never designed an airplane part before, let the real designers do the work!
 
SlimChance
Posts: 61
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RE: B787 Livery Change Enhances Airplane Performance

Wed Jul 12, 2006 11:04 am

Quoting RoseFlyer (Reply 44):
1/sqrt(f)=-1.8log([((e/D)/3.7)^1.11+6.9/R]

Thank you, you reminded me that I need a good stiff drink. Big grin
 
GBan
Posts: 488
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RE: B787 Livery Change Enhances Airplane Performance

Wed Jul 12, 2006 1:37 pm

Quoting MCIGuy (Reply 7):
Last check showed that the 787 is indeed around 1% over the target weight. Boeing is working to reduce the weight, but is also making aerodynamic and other improvements to offset it. This is not uncommon.

The article (Seattle Post) quoted in this thread says 2.5%:
Article: Lightning Protection On The B787 (by Grantcv Jul 12 2006 in Civil Aviation)
 
willyj
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RE: B787 Livery Change Enhances Airplane Performance

Wed Jul 12, 2006 2:07 pm

Quoting Ikramerica (Reply 42):
But it all comes down to pax flown, not planes.

Planes sitting still do nothing. Only when they fly pax do they achieve anything. So costs are thought of on a per pax basis.

Okay, great. But regardless, the estimated savings are $60k per plane per year - and that's actually what the airlines would save. As a passenger $.50 seems insignificant, but when you multiply that by thousands of passengers, the numbers add up. I would imagine that the airlines are looking at the bigger picture - wouldn't you?

The airlines see it as SAVING $.50 per passenger, if that makes you happier - either way, it's $60k per plane per year...
 
jacobin777
Posts: 12262
Joined: Sat Sep 11, 2004 6:29 pm

RE: B787 Livery Change Enhances Airplane Performance

Wed Jul 12, 2006 2:27 pm

Quoting RoseFlyer (Reply 44):

Sorry I'm an idiot. I should have paid more attention in college classes. I was talking about the Haaland equation, which lets you determine the roughness of a surface. For those of you curious what I'm talking about, this is the equation that somehow they solved for gray paint:

1/sqrt(f)=-1.8log([((e/D)/3.7)^1.11+6.9/R]

no apologies needed... Smile

eek..this looks like an engineering problem....I'll take Quantum Mechanics instead for $500 please... biggrin 
"Up the Irons!"
 
ikramerica
Posts: 13730
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RE: B787 Livery Change Enhances Airplane Performance

Wed Jul 12, 2006 2:34 pm

Quoting Willyj (Reply 47):
The airlines see it as SAVING $.50 per passenger, if that makes you happier - either way, it's $60k per plane per year...

No, it's not.

If the plane doesn't fly, you save ZERO dollars per plane.

My $0.50 per pax is based on utilizing the plane well. The worse you do at that, the more it costs per pax to have a livery on the engine.
Of all the things to worry about... the Wookie has no pants.

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