New winglets for A320

edwin · Post by **edwin** » 09 Apr 2006, 17:41

ya well basically winglets, it would be good to fit them on the A380 so atleast the big bird attract more companies

SAS_MD80 · Post by **SAS_MD80** » 09 Apr 2006, 18:34

Right, doesn't make much sense to me either.
The answer may lie in the fact that blended winglets are heavier and may affect the balance of the A380's wing.

Ovostar · Post by **Ovostar** » 09 Apr 2006, 19:24

edwin wrote:yes but how would it be too wide if the winglets are vertical?

I tought like you , but then AVRO showed me the truth here:

Avro wrote:
Ovostar wrote:Ok, thank you!
but... I still don't understand, Wings with small or big winglets have the same size. So big winglets wouldn't change the size of the wings, so i don't see the connection with the 80*80m box
Have a look at the two following shots and you'll see what I mean:

http://www.airliners.net/open.file/936011/L/

http://www.airliners.net/open.file/923805/L/

Chris

Bracebrace · Post by **Bracebrace** » 09 Apr 2006, 21:09

Installing winglets, and which type and size is, as with any design question in aviation, a matter of finding a good compromise. Nothing is exact, it's a question of what is important to the airline, and what is not. Every airline is different. This is shown very clearly with the 737NG, where it's an option, an option with a history. Initially Boeing developed it for the BBJ only. If you see a 737 BBJ without blended wing, it's boring, it doesn't say: "hey, I'm special". It says: "I bought a second hand commercial airliner". Put a 737 next to a Gulfstream V and everyone watches the GV. The blended wing was primarily designed only for the BBJ, and the primary design issue was: eye-catcher. An eye-catcher that would also provide fuel savings on long range flights, but it was not the primary goal. Nobody buying the BBJ was going to consider 2% fuel savings.

When they started testing the blended wing, it was found the fuel savings were a lot higher than predicted. By that time the passenger NG series was already finalized and no blended wing was foreseen. Hushkits were developed , but I think the first hushkits were not even Boeing? Only a few years later, it became an option for the NG series.

It all depends on what the customer want's to do with the aircraft, what is the goal of the aircraft? You can install 2 winglets of 50kg, but that means also that on every flight, you have to uplift 100kg extra load that doesn't pay money. 100kg more empty weight of your aircraft. 100kg less that brings in money. Perhaps winglets would allow an increase of MTOW, but this means new certification, and this takes time and money. However once you get a winglet up in the air, in cruise, it might be a benefit. Is the benefit larger than that 100kg of paying payload you lost? That's all a question of finding a good compromise, and that's not easy since it depends on what the company thinks is important.

The biggest question is always: what's the best compromise? The know-how, the knowledge of engineers, the possibilities of computational fluid dynamics create the possible possibilities. The final result is always a compromise that suits the needs of the customer best at the time of design. There's always an evolution in what engineers can do or create, but at one point you need to "fix" your design, even though you know tomorrow you will be able to optimize the design with new software, new hardware, new materials,...

Another nice example is the exhaust mixer on the CFM56 installed on the A340, with the longer cowlings. It's all extra weight that you need to uplift every time the aircraft flies. But the increased thermal efficiency at high altitude provides fuel savings in cruise, where it spends a lot of time. The A320 CFM56 does not have that exhaust mixer (even though it would give increased fuel efficiency at high altitude, it doesn't spend enough time up there during 1 flight). It's all a compromise...

SAS_MD80 · Post by **SAS_MD80** » 09 Apr 2006, 21:24

Thank you, that was an articulate, non-partisan post in this forum... for a change.

Avro · Post by **Avro** » 09 Apr 2006, 21:28

fokker_f27 wrote:If one would really want to make an efficient plane, you could add tailets like on the Raytheon Beech 1900. But that's probably too expencive.

The reason to have the tailets on the lower surface of the horizontal tailplane on the Beech 1900 is not the same as the reason to put winglets on the wing. First of all the tailets are not placed at the tip of the horizontal tailplane, they won't reduce the induced drag, and won't reduce the "magnitude" of the induced vortex at the tip. By putting tailets on the horizontal tailplane you don't make your plane more efficient like with a winglet. So it's totally false to say that you would make planes more efficient by just adding some tailets. Stabilons and ventral fins also have their dedicated purpose which is not the same as a winglet.

The reason why the Beech 1900 has tailets is mainly due to the fact that it has a fixed horizontal stabilizer. In other words you don't have a trimmable stabilizer controlled by a jackscrew. This means that more emphasis will be put on the design of your elevator, since all the pitch control will be done by your elevator.
Now the tailets are there to reduce outward airflow toward the tips. This will make your elevator more effective, especially for certain flight conditions.

It's more like a vertical fence, you see on some older planes. You will try to keep the flow attached longer and in more severe flight conditions.

edwin wrote:ya well basically winglets, it would be good to fit them on the A380 so atleast the big bird attract more companies

It's not about looks but about figures that airlines buy an airplane. And if the A380 performs as they want it to perform they wil buy it whether it has "big" winglets (like the A340) or NOT.

Ovostar wrote:I tought like you , but then AVRO showed me the truth here:

Don't forget my small computation

All this knowing of course that the span of an A380 is 79.8m which means that you would only have 10 cm of available space.

Avro wrote:
bigjulie wrote: :shakehead: I can not see how having winglets effects the 80m box; winglets go up straight, or at a bit of an angle, they don't increase the actual outward wing length.
Winglets most of the time don't go up at an angle of 90° with respect to the wing. Look at the A330 or A340 winglets. Now when the angle is smaller then 90° the span of your plane will automatically increase by a factor of cos(a)*l (of l is the length of the winglet and a the angle).

Chris

Avro · Post by **Avro** » 09 Apr 2006, 21:32

Welcome to the forum Bracebrace and with an interesting contribution. I just saw your post after writing mine.

I totally agree with you when you say that it's all about compromises in aviation

Chris

edwin · Post by **edwin** » 09 Apr 2006, 23:29

will the winglets be an option for the 787? doesn't look attractive on the 787

SAS_MD80 · Post by **SAS_MD80** » 09 Apr 2006, 23:32

Plus I'm not sure blended winglets would be compatible with that curved wing of the 787...

burner737 · Post by **burner737** » 10 Apr 2006, 00:40

To edwin

There won't be blendet winglets on a 787 ...
Look at the 777-200LR and the 767-400 ... just take a view @ the end of it's wings ... What you see is even more fuel saving like the blendet winglets like we know from the 737, 757 and now the A320 ...

Regards Tim

SAS_MD80 · Post by **SAS_MD80** » 10 Apr 2006, 07:36

And FYI Boeing has also equipped the 777-300ER and the upcoming 747-8 with raked wingtips.

edwin · Post by **edwin** » 10 Apr 2006, 11:06

will airbus put the BW on the rest of the A320 series and porbably the A330?

SAS_MD80 · Post by **SAS_MD80** » 10 Apr 2006, 18:30

I guess it depends on the result of the ongoing tests on the A320...

edwin · Post by **edwin** » 10 Apr 2006, 19:47

i think airbus should stick to its orginal tip of wings, too many other companies have blended winglets....

Bracebrace · Post by **Bracebrace** » 10 Apr 2006, 20:51

What to make up of all internet rumours and info on Airbus site:

The same thing that happened when the NG came out, is now happening with the A320. (Had to look this up) first flight 737-800 in '97. The blended winglet for the BBJ was a design of a company already mentioned here I think (Aviation Partners Boeing, but don't shoot me if I'm wrong). The launching customer (Hapag-Lloyd for the -800) was very interested in the blended winglet technology of the BBJ on their fleet and provided one of their 737-800's for flight testing. First flight of that modified aircraft was 2000 (according to Boeing's website). If I recall correctly, Boeing was not even interested at first?

But this evolution has shown you can get nice fuel savings for companies doing fairly long flights with aircraft like A320/737. Boeing had Hapag-Lloyd, now there's Jetblue wishing to modify the current winglets on their A320 fleet. The very first A320's in commercial use did not have the winglets, and the pointed version installed afterwards apparently has a very limited efficiency. Jetblue has given one of their A320 aircraft to Airbus for testflights with new technology. There was one possible design: the same design as used on the 737NG (same company). This has probably given a huge ego conflict at Airbus and they decided to design their own winglet. These two versions will now be tested in flight, and the winning winglet will be installed on the Jetblue A320's and offered as a modification for all existing (and future) A320's.

PS: these are the internet rumours. Facts are on the Airbus website.

edwin · Post by **edwin** » 10 Apr 2006, 23:08

thank you for ur thoughts

i learned a few things, do u think b737 will outbeat the A320 at a point

Bracebrace · Post by **Bracebrace** » 11 Apr 2006, 11:21

edwin wrote:do u think b737 will outbeat the A320 at a point

To be honest, I don't think you can compare both aircraft. Both are fantastic designs with completely opposite filosophy in mind. A320 versus B737 is Innovate versus Simplify. There are pro's an con's on both sides depending on which department of the company you are working in

.

edwin · Post by **edwin** » 11 Apr 2006, 14:50

ok i guess but i mean they are 'meant' for each other....A340-777 A380-747 n so on

HorsePower · Post by **HorsePower** » 14 Apr 2006, 01:07

edwin wrote:will the winglets be an option for the 787? doesn't look attractive on the 787

So far, only the -3 version will be fitted with blended winglets, in order to minimize the aircraft's span.

Seb.

CX · Post by CX » 20 Apr 2006, 13:41

i thought the whole wing is bent anyway on the 787...