LY777 From France, joined Nov 2005, 2448 posts, RR: 2 Posted (6 years 10 months 2 weeks 5 days 13 hours ago) and read 14574 times:
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."
AAgent From United States of America, joined Mar 2001, 560 posts, RR: 15 Reply 1, posted (6 years 10 months 2 weeks 5 days 13 hours ago) and read 14484 times:
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.
NYC777 From United States of America, joined Jun 2004, 5160 posts, RR: 49 Reply 2, posted (6 years 10 months 2 weeks 5 days 13 hours ago) and read 14484 times:
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.
Ikramerica From United States of America, joined May 2005, 21029 posts, RR: 60 Reply 3, posted (6 years 10 months 2 weeks 5 days 13 hours ago) and read 14448 times:
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.
Of all the things to worry about... the Wookie has no pants.
AirMailer From United States of America, joined May 2006, 413 posts, RR: 0 Reply 4, posted (6 years 10 months 2 weeks 5 days 12 hours ago) and read 14117 times:
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.
DLSLC From United States of America, joined Jan 2005, 86 posts, RR: 1 Reply 5, posted (6 years 10 months 2 weeks 5 days 12 hours ago) and read 14078 times:
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 From United States of America, joined Jun 2004, 5160 posts, RR: 49 Reply 6, posted (6 years 10 months 2 weeks 5 days 12 hours ago) and read 14048 times:
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.
MCIGuy From United States of America, joined Mar 2006, 1936 posts, RR: 0 Reply 7, posted (6 years 10 months 2 weeks 5 days 12 hours ago) and read 14013 times:
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.
Gregarious119 From United States of America, joined Jun 2006, 523 posts, RR: 0 Reply 8, posted (6 years 10 months 2 weeks 5 days 12 hours ago) and read 13875 times:
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?
MCIGuy From United States of America, joined Mar 2006, 1936 posts, RR: 0 Reply 9, posted (6 years 10 months 2 weeks 5 days 12 hours ago) and read 13790 times:
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?
Oly720man From United Kingdom, joined May 2004, 6191 posts, RR: 11 Reply 10, posted (6 years 10 months 2 weeks 5 days 12 hours ago) and read 13733 times:
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.
MCIGuy From United States of America, joined Mar 2006, 1936 posts, RR: 0 Reply 12, posted (6 years 10 months 2 weeks 5 days 12 hours ago) and read 13672 times:
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?
Baron95 From United States of America, joined May 2006, 1335 posts, RR: 9 Reply 13, posted (6 years 10 months 2 weeks 5 days 12 hours ago) and read 13660 times:
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
Grantcv From United States of America, joined Apr 2005, 429 posts, RR: 0 Reply 14, posted (6 years 10 months 2 weeks 5 days 10 hours ago) and read 13354 times:
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 From United States of America, joined Jun 2006, 81 posts, RR: 0 Reply 15, posted (6 years 10 months 2 weeks 5 days 9 hours ago) and read 13223 times:
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 From United States of America, joined Jun 2006, 88 posts, RR: 0 Reply 16, posted (6 years 10 months 2 weeks 5 days 8 hours ago) and read 12720 times:
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 From United States of America, joined May 2005, 21029 posts, RR: 60 Reply 17, posted (6 years 10 months 2 weeks 5 days 8 hours ago) and read 12555 times:
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.)...
Of all the things to worry about... the Wookie has no pants.
Centrair From Japan, joined Jan 2005, 3597 posts, RR: 21 Reply 18, posted (6 years 10 months 2 weeks 5 days 7 hours ago) and read 12376 times:
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?
Yes...I am not a KIX fan. Let's Japanese Aviation!
Glennstewart From Australia, joined Jun 2003, 1124 posts, RR: 56 Reply 19, posted (6 years 10 months 2 weeks 5 days 7 hours ago) and read 12171 times:
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
Respected users.... If my replies are useful, then by all means...
BoeingBus From United States of America, joined May 2004, 1588 posts, RR: 18 Reply 20, posted (6 years 10 months 2 weeks 5 days 6 hours ago) and read 11663 times:
DfwRevolution From , joined Dec 1969, posts, RR: Reply 21, posted (6 years 10 months 2 weeks 5 days 6 hours ago) and read 11428 times:
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 From United States of America, joined May 2005, 21029 posts, RR: 60 Reply 22, posted (6 years 10 months 2 weeks 5 days 6 hours ago) and read 11389 times:
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.
Of all the things to worry about... the Wookie has no pants.
ChrisNH From United States of America, joined Jun 1999, 3807 posts, RR: 2 Reply 23, posted (6 years 10 months 2 weeks 5 days 5 hours ago) and read 10752 times:
AAgent From United States of America, joined Mar 2001, 560 posts, RR: 15 Reply 24, posted (6 years 10 months 2 weeks 5 days 5 hours ago) and read 10693 times:
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
War Eagle!
25 Zamaria: 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 at
26 WingedMigrator: What a brilliant idea! Sounds like something that could be applied to the tail as well! More seriously, how can this possibly matter compared to cowl
27 Centrair: 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
28 DfwRevolution: Right: Any solid color will have a slight aerodynamic advantage over an engine nacelle with decals or paintlines. Boeing has simply chosen a grey sha
29 Grbld: 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 m
30 Gary2880: 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 o
31 Molykote: 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
32 MCIGuy: 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 Boe
33 Vzlet: All of these queries/points... ...were addressed in the initial post:
34 DfwRevolution: Yeah I was clarifying it for someone who asked. Way to waste text and be a tool...
35 DAYflyer: Talk about fine tweaking an airplane before roll out, wow.
36 RoseFlyer: 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
37 DfwRevolution: Having just read a Flight International article on this topic, it would appear to conflict with what I assumed from the Boeing press relase: Accordin
38 Scouseflyer: 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,
39 RoseFlyer: 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! That
40 FriendlySkies: I doubt only grey paint can be used...I mean, is blue paint chemically "thicker" than grey?
41 Willyj: or you could look at it as $60,000 per plane per year...
42 Ikramerica: 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 though
43 Jacobin777: actually the henderson-hasselbach equation is quite straightforward, especially in the presence of a strong buffer..
44 RoseFlyer: 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 roug
45 SlimChance: Thank you, you reminded me that I need a good stiff drink.
46 GBan: 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)
47 Willyj: 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 $.5
48 Jacobin777: no apologies needed... eek..this looks like an engineering problem....I'll take Quantum Mechanics instead for $500 please...
49 Ikramerica: 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 t
50 VirginFlyer: I read that as meaning the paint was a specific thickness all the way around with no discontinuities, not that there was a specific thickness the pai
51 Rheinbote: While everyone was quick to point out what the benefit would be, how about the cost of - elminiating all access panels, orifices and protuberances wi
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