Talk:Wingtip device/Archive 2

I am uninformed about stuff like this, but have actually been vaguely curious about winglets that I've seen on planes at an airport near to me, and I arrived at this article today to try to make sense of statements in obituaries today about death of aerospace pioneer Joe Clark (aeronautics) (new stub article). One obituary mentioned his role "perfecting and selling blended winglets" that reduce drag and improve performance of more than 9,000 private and commercial jets (per Seattle bizjournals obituary, March 31, 2020).

However I was derailed by the article having a long-standing nonsensical/ungrammatical statement, about a winglet being used during World War II production of He 162 planes: "This was done in order to counteract the dutch roll characteristic the marked three degrees of dihedral angle for each wing panel that the original He 162 design's wings possessed." I cannot parse that, I think it does not make sense as a sentence. The sentence became garbled in this 21 December 2016 edit by User:The PIPE, which unfortunately modified the original coverage of the issue for the He 162, added 18 June 2014 by The PIPE.

I added a link to the dihedral (aeronautics) article, moved the paragraph, and broke it into shorter sentences, and otherwise edited it in this diff just now to become the following:

The earliest-known implementation of a Hoerner-style downward-angled "wingtip device" on a jet aircraft was during World War II. This was the so-called "Lippisch-Ohren" (Lippisch-ears), allegedly attributed to the Messerschmitt Me 163's designer Alexander Lippisch, and first added to the M3 and M4 third and fourth prototypes of the Heinkel He 162A Spatz jet light fighter for evaluation. This addition was done in order to counteract the dutch roll characteristic present in the original He 162 design, related to its wings having a marked dihedral angle. This became a standard feature of the approximately 320 completed He 162A jet fighters built, with hundreds more He 162A airframes going unfinished by V-E Day.^[1]

Is that okay now?

There was also a "citation needed" tag added September 2016 with "reason=cited source does not support claim that these act as wingtip devices", which I don't understand. I suppose a winglet might be considered a "wingtip device", right? Then the complaint is about how the source does not support the wingtip device being a wingtip device? I know that I am uninformed in this subject area, but I removed the "citation needed" tag. Perhaps someone more knowledgeable could review this sourcing issue? The citation needed tag followed this sentence: "As production of the Third Reich's chosen turbojet-powered emergency fighter was of prime importance at the start of 1945, disruption of the production line to make other types of changes to correct such a problem were not likely to have been available, and the added wingtip devices became a standard feature of the approximately 320 completed He 162A jet fighters built, with hundreds more He 162A airframes going unfinished by V-E Day" which was attributed to the J. Richard Conway 1972 source. The sentence partially duplicated info in a previous sentence. And to me, the sentence appeared speculative, anyhow, and I am suspicious that it was speculation by the Wikipedia editor, so I removed the sentence entirely. (I may be wrong, i.e. if the source does talk about changes being "not likely to have been available", then my uninformed removal should probably be reversed.) --Doncram (talk) 18:21, 1 April 2020 (UTC)

The following Wikimedia Commons file used on this page or its Wikidata item has been nominated for speedy deletion:

• Different winglets and sharklets .jpg

You can see the reason for deletion at the file description page linked above. —Community Tech bot (talk) 01:52, 23 July 2020 (UTC)

@BilCat:, I kinda nerded out a bit there, didn't I? This page is so bad! Anything substantive kinda stands out. But this tech is so interesting. Raynatravis (talk) 04:43, 18 March 2021 (UTC)

No worries, but it needs to be proportionate and neutral in scope. I'll try to read the sources tomorrow and see what can be kept, if anything. BilCat (talk) 04:48, 18 March 2021 (UTC)

I think the article would benefit from an explanation of “active wingtip” but the emphasis on a brand name, and the claims about extraordinary feats of performance, are inappropriate in an encyclopaedia. Dolphin (t) 04:56, 18 March 2021 (UTC)

I quote the inaccurate sections from the first two paragraphs of the wiki-page:

"[Wingtip devices] intended effect is always to reduce an aircraft's drag by partial recovery of the tip vortex energy."

"Partial recovery of the energy" in the very least needs clarification and a source. I'd argue that is inaccurate, see McLean, Doug (2005). Wingtip Devices: What They Do and How They Do It (PDF). 2005 Boeing Performance and Flight Operations Engineering Conference.

"Such devices increase the effective aspect ratio of a wing without greatly increasing the wingspan. Extending the span would lower lift-induced drag, but would increase parasitic drag and would require boosting the strength and weight of the wing."

Wingtip devices also result in parasitic drag, it doesn't matter if the wetted area is vertical or horizontal. Wingtips also add weight and can increase the bending moment on the wing.

"...the winglet also reduces the lift-induced drag caused by wingtip vortices" - Vortices do not impact the lift-induced drag, they are a result of it. See McLean, Doug (2005). Wingtip Devices: What They Do and How They Do It (PDF). 2005 Boeing Performance and Flight Operations Engineering Conference. FropFrop (talk) 06:09, 7 June 2023 (UTC)

The user @Dolphin51, replied to another talk topic I started in the related page wingtip vortices, they corrected me on an inaccuracy I made in the text above, which I have copied and pasted below:

"I agree that some extra clarity would be desirable. However, your understanding that “induced drag causes the vortices” is immature. This style of thinking about matters of physics is highly inaccurate. When an airfoil is inclined to a flowing fluid so that it has an angle of attack, many things happen - lift occurs, drag increases, the fluid velocity around the airfoil acquires a spanwise component, a vortex sheet develops, trailing vortices develop, downwash occurs, orientation of the lift and drag vectors changes, lift-induced drag occurs, and so on! There are other changes too, that I haven’t mentioned. To select one of these (such as induced drag) and suggest that it causes one of the others (such as trailing vortices) is incorrect. All these things occur simultaneously as a consequence of changing the angle of attack on the airfoil. There is no other cause-and-effect, and there is no time lag between them as is sometimes suggested. This principle is not unique to fluid dynamic lift; it is true of most phenomena of interest in physics."

I believe most of what I said is still relevant when it comes to potential improvements in the page.

FropFrop (talk) 06:59, 8 June 2023 (UTC)

There is no single, correct explanation of induced drag; there are several explanations, all satisfactory. Similarly there is no single, correct explanation of the way wingtip devices reduce induced drag; there are several explanations, all satisfactory. It is inappropriate for the lead to this article to state that these devices operate by partial recovery of tip vortex energy. This might be one satisfactory explanation but it certainly isn’t the only one. Drag is a force but energy is not, so attempting to explain drag in terms of energy is not consistent with WP:Make technical articles understandable. I have erased the offending words. Dolphin (t) 11:02, 8 June 2023 (UTC)