Talk:Delta wing/Archive 1

Archive 1

Advantages

"The primary advantage of the delta wing design is that the wing's leading edge remains behind the shock wave generated by the nose of the aircraft when flying at supersonic speeds, which is an improvement on traditional wing designs."

Isn't this just a matter of the sweep rather than the delta planform? For example, the English Electric Lightning and MiG-19 have rather severe leading edge angles for this reason, even though they are not deltas. -- Paul Richter 09:52, 22 Nov 2004 (UTC)

The delta wing has much the same advantage as the swept wing: primarily a delay of critical Mach of 1/cos(angle of sweep)

The wing is as if it were flying at reduced speed, reduced Mach number, and reduced dynamic pressure.

 effective speed = V cos(L)
 effective Mach  = M cos(L)
 effective q     = 0.5 rho V^2 [cos(L)]^2

where L is the sweep angle, V the airplane's speed and M its Mach, rho the air density and q the dynamic pressure.

The dynamic pressure term shows that the wing will have not only reduced drag but also reduced lift since:

Lift = Cl x A x q where Cl is the coefficient of lift and A the Area Drag = Cd x A x q where Cd is the coefficient of drag and A the Area

Suppose a swing wing aircraft is flying at its critical Mach number. If the wing then is swept back from 0 to L degrees the lift reduces by a factor of [cos(L)]^2, and the Mach compressibility effects on the wing's airfoils decrease eg shock wave formation. It is then possible to increase the speed by a factor of 1/cos(L).

These are simplifications for a swept wing; deltas are similar but far more complicated in real life due to the formation of vortices at the leading edge root that has a positive influence on handling and lift.

Alexander Lippisch

I don't know why Dr Alexander Lippisch is not mentioned in regards to the Delta wing: he had developed flyable swept wings in the 1930s and 1940s and proposed a surpersonic delta in 1940. In 1945 his DM-1 glider was shipped to the USA for study. His P.13a represents perhaps the first proposal to develop a supersonic delta.—Preceding unsigned comment added by Frederick Munster (talk • contribs)

You are right. The reference to Neythen Woolford is a furfy I believe. He is a kid on facebook and appears in no other published histories of Delta wings I have ever read. I'm suspect someone has vandalised the entry and sustituted their own name to achieve notoriety. It is demonstrable that Lippisch was the pioneer of Delta wings in Germany prewar and postwar GregOrca (talk)

The article is pretty disorganized. It should talks about Adolf Busemann theory, and the work of Alexander Lippisch and the theory of Robert Thomas Jones. The value of Lippisch and the Germans was not the DM-1, which is often misunderstood, it was just a plywood glider that was never flown and only tested to 45 mph in Langley's wind tunnels. Folks see the photos of the DM-1 and jump to conclusions. What was important about the German work was the supersonic wind tunnel studies on swept wings and delta wings, which was found by Von Karman. This article completely fails to discuss the history of the topic very well. DonPMitchell (talk) 23:54, 6 April 2014 (UTC)

Carnard

The explanation of the canard in the 3rd paragraph is a bit confusing. I've cleaned up the language a bit, but the point is still unclear. Attributing designs incorporating canards to unstable platforms and FBW doesn't seem accurate. The F-117 and F-16 are inherently unstable and neither have canards. FBW and instability (due to more radical, effective designs) do exist symbiotically these days, but that is independent of canard use. While the EF-2000, Rafale, etc. are more advanced designs and use canards, that has more to do with the increased effectiveness of delta-wing aircraft with canards, not necessarily instability or FBW.--Jonashart 20:13, 27 July 2006 (UTC)

That 3rd paragraph reads much better now. Sorry, took a while to get back to reading it. Nicely done, whomever is responsible.--Jonashart 15:44, 19 April 2007 (UTC)

We're still missing something on canard trim. Canards are trimmed to increase lift while conventional tails are trimmed to reduce overall lift. I'm still looking for the best ref for this. Any suggestions? Hcobb (talk) 01:23, 13 February 2011 (UTC)

Reorganise?

The article seems to alternate between historical ordering and description.

Perhaps the better structure would be:

1. history
   1. before WWII
   2. later development
   3. current status
2. discussion
   1. advantages
   2. disadvantages
3. list of types

m.e. 05:25, 24 November 2006 (UTC)

Support. - BillCJ 05:41, 24 November 2006 (UTC)

suggested in the 17th century by Polish inventor?

Claims that Kazimierz Siemienowicz had pioneered delta wings had been rejected [1] before, but were re-introduced once again [2], giving e.g. a NASA source that says .... proposed ... delta-shaped stabilizers to replace the guiding rods.... These stabilizers are simple fins, as on an arrow, not large lift-creating wings for a supersonic airplane. The sources do not back up the claim "Conception of this wing and its name" and the addition to Category:Polish inventions. -- Matthead  Discuß   11:09, 20 July 2009 (UTC)

If that is the case, be WP:Bold and remove the claims. --TraceyR (talk) 13:40, 10 November 2009 (UTC)

"undesirable characteristics"

This sentence seems to be complete rubbish:

"Pure delta-wings fell out of favour somewhat due to their undesirable characteristics, notably flow separation at high angles of attack"

Flow separation at a high angle of attack is exactly what is desirable....

Flow separation will always occur over a wing at a certain angle of attack. The higher the better...

This needs to be deleted or changed. Jez 006 (talk) 16:35, 15 April 2010 (UTC)

The point is that the part is about: "Pure delta-wings". It is not wrong. It is a relative statement. We are talking about very high attack angles of up to 60°, where a plain delta is not as good as a wing with leading-edge extension or canard or other irregularities. --95.116.222.102 (talk) 10:58, 11 December 2012 (UTC)

I agree that pure delta wings have fallen out of favour when compared with other planforms. I disagree that this is due to flow separation at high angles of attack or any other undesirable characteristic. This looks like somebody's original research. All wings exhibit flow separation at high angles of attack, not just delta wings. In fact, there are grounds for saying it is conventional wings that exhibit flow separation at high angles of attack leading to a stall, whereas delta wings don't exhibit a stall so flow separation can't be a problem.

Any discussion about the decline in popularity of the pure delta wing doesn't belong under the heading Delta-wing variations. Dolphin (t) 05:01, 18 April 2010 (UTC)

The sentence is the introduction/motivation for variations of the simple geometry. It does make sense here. --95.116.222.102 (talk) 10:58, 11 December 2012 (UTC)

Glad you agree. It is the case that pure delta wings experience flow separation at lower angles of attack than double delta wings, delta wings with canards or delta wings with a chinard configuration, but this is not what has been written! I'll change it soon Jez 006 (talk) 11:03, 18 April 2010 (UTC)

It seems this paragraph is mostly incorrect as well:

"Another advantage is that as the angle of attack increases the leading edge of the wing generates a vortex which remains attached to the upper surface of the wing, giving the delta a very high stall angle. A normal wing built for high speed use is typically dangerous at low speeds, but in this regime the delta changes over to a mode of lift based on the vortex it generates. The disadvantages, especially marked in the older tailless delta designs, are a loss of total available lift caused by turning up the wing trailing edge or the control surfaces (as required to achieve a sufficient stability) and the high induced drag of this low-aspect ratio type of wing. This causes delta-winged aircraft to 'bleed off' energy very rapidly in turns, a disadvantage in aerial maneuver combat and dogfighting. This can be solved with relaxed stability, strakes and canards.[citation needed]"

For example:

"Another advantage is that as the angle of attack increases the leading edge of the wing generates a vortex which remains attached to the upper surface of the wing, giving the delta a very high stall angle"

As the angle of attack increases from what? It remains attached until when? Yes they generally have a higher stalling angle than conventional aerofoils but just to say a "very high stall angle" is pretty misleading... What defines a " very high" stall angle?

"A normal wing built for high speed use is typically dangerous at low speeds, but in this regime the delta changes over to a mode of lift based on the vortex it generates"

Delta wings are especially dangerous at low speeds, more so than normal wings. At lower speeds delta wings produce less lift and more drag than normal wings... This is why delta wings are more difficult to land, because at low speeds they experience a sudden loss in lift. This is why the concorde had such a high landing speed.

For that I would have to see a credible source and explanation to believe. --95.116.222.102 (talk) 10:01, 11 December 2012 (UTC)

"The disadvantages, especially marked in the older tailless delta designs, are a loss of total available lift caused by turning up the wing trailing edge or the control surfaces (as required to achieve a sufficient stability) and the high induced drag of this low-aspect ratio type of wing. This causes delta-winged aircraft to 'bleed off' energy very rapidly in turns, a disadvantage in aerial maneuver combat and dogfighting. This can be solved with relaxed stability, strakes and canards.[citation needed]"

I can't agree or disagree with this, but there are no references. Since the previous sentences are not correct I doubt the accuracy of anything else that has been written.

Jez 006 (talk) 11:59, 18 April 2010 (UTC)

I agree with parts of the critique and would like to point out that the issue persists. Please don't use white lines within your post, but only to separate it from others. --95.116.222.102 (talk) 10:01, 11 December 2012 (UTC)

"It also causes a reduction in lift at takeoff and landing until the correct angle of attack is achieved, this means that the rear undercarriage must be more strongly built than with a conventional wing." what does a more strongly built undercarriage have to do with compensating for reduced lift? please modify article to explain thanks 24.98.133.72 (talk) 04:19, 18 August 2014 (UTC)

Conrad who?

I have read everything I could find on Conrad Haas and nowhere does it say he investigated or experimented with wings of any kind. All the documents ever talk about is triangular fins. I'm sure someone is going to tell me wings and fins are one and the same. They're not. All fins do is line up into the wind behind the center of gravity. The whole purpose and function of a wing is different. Wings support the weight of the air vehicle to which they are attached, and they do it specifically by not lining up into the wind but by assuming a non-zero angle across the wind vector so as to deflect air downward, lift being the "equal and opposite reaction" to the downward deflection of the air. So what the heck does Conrad Haas have to do with the invention of the delta wing? You don't need to know anything about flight trim to make a fin work, but if you don't know flight trim, you don't know the aerodynamics of winged flight. Sorry Conrad, but you did not invent the delta wing. Maybe it was the butterfly that just landed on your shoulder.Magneticlifeform (talk) 01:23, 20 October 2010 (UTC)

This article is a dud and will remain so as long as Conrad Haas and other content of contrived relevance is perpetuated. Too bad so many articles have to go through this stage. It certainly slows things down.Magneticlifeform (talk) 04:54, 9 December 2010 (UTC)

Moved those to sub-section and changed "wings" to "stabilizers" for clarity. --Kubanczyk (talk) 01:30, 13 February 2011 (UTC)

Wings and fins are one and the same. While the purpose of a fin is different from a wing, its function is the same. It lines up behind the CG because any disturbance from that position puts it at a non-zero angle across the wind vector (angle of attack) such that it creates a force normal to the wind vector (lift) in a direction that returns it to its original position behind the CG. Since a fin is a wing, any R&D on fins is therefore relevant to wings. Vessbot (talk) 03:07, 2 October 2014 (UTC)

Some good info.

Found some very good and concise, seemingly very legit info on deltas (and other wings) here: http://aerostudents.com/files/advancedAircraftDesign/AdvancedAircraftDesign2Summary.pdf . Can someone tell me if this is okay for a reference? Seems legit to me, and very balanced and fair, factual. .45Colt 01:41, 14 April 2014 (UTC)

The Last Laugh

The homebuild machine which Scroggs named "The Last laugh" is not a delta type because a large chunk of its nose is missing, it is more a low-aspect-ratio straight wing with angled tips. Just because Scroggs also worked on a delta version does not make this one a Delta. His own account and those derived from it, such as journal pieces, are not reliable sources. If this plane is to be included here then far better sourcing is necessary to verify the claim that it is a delta design. — Cheers, Steelpillow (Talk) 16:40, 2 July 2018 (UTC)

Wrong! The cut in wing nose of 'Flying Dart', the Roy B Scroggs 'The last laugh!', makes it identical to the double angle of swept Delta Plan Wing in Saab Draken, the Draken has there air intakes to the turbine, the cut in Scroggs Dart's nose is for room to the propeller, moved by the OX-5, the rounded wingtips are a variant of 'Cropped Delta'. Should I remark to you that the subject is not semantics, but the history of aviation? The fact that Scroggs was a tailor doesn't mean his work lacks any value, Robert T Jones, a pioneer in Delta Wing aerodynamics, had no academic background; even if Scroggs built just one prototype, his work is at least comparable to early work from the French Payen. Aerofiles and other sources describe well the flight of Scroggs Delta, which had same 75º sweptback, as remarked, to the Handley Page HP.115. Is there any special thing in this right entry that makes you upset? Thanks. Gesund +

btw: only persons can be 'christened', animals, objects, 'are given a name', please correct, this is an insult to believers! Restrictions of freedom of expression, deviations from reality, are much more important in an Encyclopedia than hard language, standards for this vary a lot depending on your country, neighborhood, school, age, mood, general health, sleep quality, weather,... — Preceding unsigned comment added by Hijuecutivo (talk • contribs) 16:02, 5 July 2018 (UTC)

Hi, thank you for replying. First the Saab Draken. I agree it is perhaps a marginal case but reliable sources describe it as a double-delta, and therefore so does Wikipedia. I have been unable to find a similarly reliable source for the Scroggs aircraft. Also, the aerodynamic cases are entirely different. At supersonic speeds the low aspect ratio of the Draken is less significant and it behaves like a delta wing. But at the low speeds of which the Scroggs might have been capable the tip effects of the low aspect ratio would have dominated the "delta" angle and it would have behaved more like a conventional low-aspect-ratio wing. So I do not anticipate finding any citations to support his description as a delta.

As for its notablility, yes I believe The Last laugh deserves a place on Wikipedia, but this article is not the right place for it. If I can find the time, I will try and look for a suitable home. I hope this helps. — Cheers, Steelpillow (Talk) 17:34, 5 July 2018 (UTC)

Update: I think it should have its own article. I have begun to draft it here. Please let me know of any more reliable sources for more information. — Cheers, Steelpillow (Talk) 21:16, 5 July 2018 (UTC)

Update: Please now see Scroggs The Last Laugh. — Cheers, Steelpillow (Talk) 07:35, 6 July 2018 (UTC)

I would like to add that the Saab Draken is likely to be a cranked-arrow delta wing (my 2 cents) TomSwansen (talk) 21:35, 29 July 2018 (UTC)

Space Shuttle

The US also used an ogival design for the Space Shuttle, which was flown in to land as an aircraft. — Preceding unsigned comment added by 90.218.129.127 (talk) 09:29, 20 July 2019 (UTC)

The Shuttle is normally classified as a double delta, due to the long straight sections between tightly curved corners. But this is not the List of delta-wing aircraft, so most examples are not discussed here. — Cheers, Steelpillow (Talk) 10:21, 20 July 2019 (UTC)

Photos

I'm a bit surprised that we don't have any photos of aircraft from two manufacturers known for producing delta-wing aircraft, Convair and Dassault. Both produced several types, both fighters and bombers. I've looked around for good shots of some of their aircraft that show the deltas to good effect, but Commons isn't very user friendly for that type of search, so I didn't find any I liked. Hopefully someone else with some extra time can find a couple of good ones. I have in mind one photo of a fighter, and one of a bomber, hopefully one from each manufacturer. - BilCat (talk) 16:31, 15 April 2020 (UTC)

I've had a go. better but not perfect. I'll try and find a Hustler in place of the F-106 if I get a minute. — Cheers, Steelpillow (Talk) 09:38, 16 April 2020 (UTC)

XF-92

My understanding is that the Convair XF-92 is the first jet delta to actually fly, so how is it that it isn't deemed significant enough to even be mentioned on this page? Not even a "See Also" link. The gist of this page seemed to be that Germans invented delta wings, the French and British and Swedes quickly copied them, producing test deltas by the late 40s and production ones by the mid 50s, while at some undefined point the Americans came up with the F-102 and F-106 and B-58. "History of the delta wing" mentions German work, French work, it mentions the Avro 707 and the Vulcan, but nothing at all about the first delta to actually fly. Seems like it merits a least a footnote or something.

64.222.126.103 (talk) 19:13, 18 July 2022 (UTC)

Thank you for pointing that out. I have added a note on the XF-82, but claims that it was the first ever jet delta would need citing from a reliable source. — Cheers, Steelpillow (Talk) 19:23, 18 July 2022 (UTC)

In adding maneuverability by steelphillow

I was told to create this, I think the maneuverability section should stay up and that the only unsourced part of sustained maneuverability is a mathematical conclusion thus shouldn’t need sourcing Bobisland (talk) 15:15, 11 October 2022 (UTC)

Thank you for coming here. But who told you to do this? Wikipedia is not a soapbox. You don't escape our policies and guidelines by being ordered to. Quite the reverse, they are designed to control such things tightly. (Oh, you meant by my edit comment? That was an advisory request, not a command. Sorry I misunderstood.)

On the content itself. You focused on low-aspect-ratio supersonic deltas, wholly irrelevant to to types such as the 1930s Lippisch deltas or the Avro Vulcan. The conclusion that such a delta is more manoeuvrable due to its inherently low wing loading is false. Firstly only the tailless delta has an inherently lower wing loading, but only by virtue of being a tailless aircraft. Secondly low wing loading does not necessarily confer manoeuvrability; other factors such as having a tail, canard, high-lift devices, low aspect ratio, etc. etc. all contribute. I could go on but I hope you get the idea. In short, you need to check the scope of your sources carefully, qualify your remarks accordingly, and stay within their statements.

If you still wish to continue, I would recommend that you fully explain your potential conflict of interest (see WP:COI). Take your proposed changes one at a time here, so each can be clarified and the best place to add it to the article can be decided on. Once you get the idea of how things work here, you will no doubt find that things get easier.

— Cheers, Steelpillow (Talk) 16:58, 11 October 2022 (UTC) [Updated 10:44, 12 October 2022 (UTC)]

“The conclusion that such a delta is more manoeuvrable due to its inherently low wing loading is false“ I said supersonic maneuverability in comparison to swept wing aircraft which is true, this doesn’t mean literally all which is implied, the other things I’ve already mentioned and I don’t know why you removed them as they’re well sourced and salvageable, this includes the poor low speed performance, low aspect ratio, structural strength, surface area and drag effecting speed when turning and etc Bobisland (talk) 19:35, 11 October 2022 (UTC)

With delta wings, context is all, and that includes the context of primary source materials. In the present article, wing loading is only relevant in so far as the delta differs from other planforms. You might want to take on board my comment that "only the tailless delta has an inherently lower wing loading, but only by virtue of being a tailless aircraft." That is, loading has nothing to do with the choice of the delta vs swept as such. What you did was to jumble different contexts and your content was not adequately supported by the sources you supplied. The burden of proof lies on the editor who posts the material, not on those who remove it. If you think I am wrong about a source, please cite the specific page/s in it which directly support your text. You might find it helpful to reconsider WP:OR, WP:BURDEN and related policies and guidelines before pursuing this further. — Cheers, Steelpillow (Talk) 10:44, 12 October 2022 (UTC)

Spanish patent of 1909, "Causarás Monoplane"

i think it would be nice to include his design, feels more coherent than earlier proposals, it actually includes a chassis and uses a canard and delta configuration https://es.m.wikipedia.org/wiki/Archivo:1.909.-_Planos_del_Aeroplano-Monoplano_Causar%C3%A1s.jpg You could say it's an evolution of the J.W. Butler and E. Edwards designs but their dual delta platform is quite not the same, if not almost the opposite. https://www.ctie.monash.edu.au/hargrave/butler.html

A 3D model is seen here: https://causaras.blogspot.com/2014/?m=1 Mirad1000 (talk) 16:59, 16 April 2023 (UTC)

Thank you for coming here. This shows the danger of imagining that one's own language's literature tells all that there is to know. This Spanish patent is new to me. It is reminiscent of Roy Scroggs' US patent of 1917, which he developed into the unsuccessful The Last Laugh, but this was eight years before him and contemporary with Dunne's UK patent on the conical delta. Yes, I can see that one of my kids or nieces is going to have to translate some Spanish for me! I must check if there is a copy on Espacenet. Meanwhile, maybe somebody else here can add a mention to the historical summary. — Cheers, Steelpillow (Talk) 18:45, 16 April 2023 (UTC)

[Update] I cannot find it on Espacenet. There are various claims on the Internet, but it is hard to verify anything from a reliable source. We may have to give this one a miss, for now at least. — Cheers, Steelpillow (Talk) 19:39, 16 April 2023 (UTC)

[Update] Aha! Patent No. 46026, http://centenariaviacio.catedradr.com/site/upload/ficheros/d-04b.pdf It is handwritten not typed. I am not familiar with the Spanish system, but it appears to be a patent *application*. If it is like the UK system, then he may not have fully registered his patent, which might explain why it is not in the EU repository. Still, it's a start. Anybody good at reading Spanish handwriting? — Cheers, Steelpillow (Talk) 01:32, 17 April 2023 (UTC)