Talk:Area rule/Archive 1

Archive 1

Comments

If there is a finer example of how collabrative editing can turn a somewhat geeky article into one of the best on the topic I've seen, I can't think of it. The images added have really improved the content a lot.

Maury 14:06, 13 Jun 2005 (UTC)

This article is very well-written, but renaming it "Whitcomb area rule" was asinine. It makes the page harder to find and to link to. ArgentLA 22:04, 20 November 2005 (UTC)

I agree about the images in general, but there are rather a lot - the 747 especially is a dubious inclusion in my view, since AFAIK, the top deck design has little to do with area rule, and more to do with other aspects of the practical design. If this were not the case, then every airliner would have a similar shape, whether or not the bulge was actually useful for passenger accommodation. And the A380 as an even newer two-deck design doesn't employ area rule in this manner. I think the 747 should go. Other photographs should be removed if they only duplicate the same point already made - the B-1 is superfluous in my view. Too many images on a page make it slow to dlownload on dial-up, and tend to distract from teh text. Illustrations and photographs should only be added to enhance an article, not take it over. Graham 02:40, 12 December 2005 (UTC)

Uhh, the 747 is a textbook example of the area rule. The aircraft was originally designed as a strategic transport competing against what became the C-5 Galaxy. Both aircraft were sized specifically to contain a 2-by-2 stack of standard shipping containers. In the case of an accident, these would come out the front of the aircraft and nothing would stop them, so in order to protect the pilots the cockpit was located above the cargo area. Lockheed chose to enclose the entire area as a second deck, leading to it's egg-shaped cross-section, while Boeing instead used the "pod". While developing the -400, testing demonstrated that extending the pod rearward would reduce drag due to the area rule. Maury (talk) 15:36, 6 January 2008 (UTC)

Uhh ... this is a horribly written text. "The area rule says that two airplanes with the same longitudinal cross-sectional area distribution have the same wave drag, independent of how the area is distributed laterally" ... I don't care who's textbook that's in - it's dumb and it's poorly written. — Preceding unsigned comment added by 98.194.39.86 (talk) 05:25, 6 October 2016 (UTC)

converted thumb to text. --Arnero 10:28, 14 December 2005 (UTC)

Otto Frenzl

I've asked User:Stahlkocher1 (on his talk page) to provide some sources for his recent edits, as I can't find anything about Otto Frenzl on google. Does anyone else know anything about this man ? Megapixie 08:42, 27 December 2005 (UTC)

See ongoing discussion on my talk page Megapixie 23:46, 27 December 2005 (UTC)

assuming the german wikipedia correct, frenzl was the original creator or the area rule.

http://translate.google.co.uk/translate?hl=en&sl=de&u=http://de.wikipedia.org/wiki/Otto_Frenzl&sa=X&oi=translate&resnum=1&ct=result&prev=/search%3Fq%3DOtto%2BFrenzl%26hl%3Den%26sa%3DG

Dietrich Küchemann

File:Airplane draft.png

Area rule 1945 on a deltawing fighter

I thing Küchemann in overestimated in the area-rule matter. The german war scientist had good connections, and so they werewell informed about real news. Küchemann and most other did now about the Junkers patent. There were severall designs working with the areal rule, even at BMW design office (sic!). So everybody knows whats going on. Most of them are late 1944 shure that there will be no Endsieg. But research was still going on. However: If Whitcomb really meet Busemann, it is most likely that Busemann plain told him about the area rule. And probably some other things. -- Stahlkocher 13:24, 3 January 2006 (UTC)

Dietrich Küchemann moved to the RAE Farnborough at the end of WW II and worked with Handley Page and was subsequently involved on the Concorde supersonic airliner project. — Preceding unsigned comment added by 80.4.57.101 (talk) 11:13, 7 February 2012 (UTC)

Research went on

I found someone with approach to the inner sight of german 1945 aircraft industrie. I thought (no document found yet) that, beside Junkers, just Messerschmidt, Arado and Heinkel (probably one or two more) had knowledge about the Frenzl patent. This means that it was not spread to much. Furthermore he suggested that the afford to get a area ruled airframe was to large if you stay subsonic. This is probably the reason while Baade did not use it in russia on his developments. The next thing is that the HP Victor most likely has an area ruled airframe, making this aircraft probably the first flying thing with this awareness. Maury told my about british researches working on area ruled bodies, but did not name them till now. I hope he will tell me soon. -- Stahlkocher 17:22, 3 February 2006 (UTC)

Article name

Shouldn't this be Whitcomb area rule? —Joseph/N328KF (Talk) 03:42, 14 January 2007 (UTC)

Why? Whitcomb rediscover only the Fenzel area rule.--HDP (talk) 10:46, 29 November 2007 (UTC)

Bernoulli?

I have just removed the unscientific "due to Bernoulli" statement. I suspect this is a version of the transit time fallacy popularized by incorrect explanations of airfoil lift. Acceleration of a fluid is not "due to Bernoulli." Applying Bernuolli's law to a supersonic flow situation is naïve. Such assertions should not be made without supporting references.

Don't put this nonsense back in without some justification.

Johnny (talk) 18:12, 18 July 2008 (UTC)

You're correct, but when you use all those "3 dollar words" - no one is going to believe you. Speak English next time, and maybe you'll convince someone that you understand the subject matter. "Transit time fallacy"? Do you speak like that at work? No. Not even if you work at Boeing or Lockmart. — Preceding unsigned comment added by 98.194.39.86 (talk) 05:28, 6 October 2016 (UTC)

Possible error in terminology

I think the term "incompressible fluid" in the following sentence should actually be "compressible fluid"

He talked about the difference in the behavior of airflow at speeds approaching supersonic, where it no longer behaved as an incompressible fluid.

207.30.62.198 (talk) 00:07, 13 October 2011 (UTC)

I agree Teknikal224 (talk) 20:08, 27 January 2014 (UTC)

The article begins by saying "The Whitcomb area rule, also called the transonic area rule ..." In a number of places the article incorrectly referred to the "supersonic area rule" so I have changed each one to transonic area rule or another more appropriate expression. See my diff.

The sentence challenged above now says Busemann talked about the difference in the behavior of airflow as speeds approached the critical Mach number, where the air no longer behaved as an incompressible fluid. I think this version of the sentence is now correct. Dolphin (t) 01:50, 28 January 2014 (UTC)

In the Description section: "The area rule says that two airplanes with the same longitudinal cross-sectional area distribution have the same wave drag..." A longitudinal cross-section would be a section cut in some plane parallel to the nose to tail axis. Is "a transverse cross-section" what is meant? Is the word "distribution" used correctly or should that word be omitted and the sentence read "...cross-sectional area have the same wave drag..."? — Preceding unsigned comment added by 68.11.234.61 (talk) 18:42, 10 October 2015 (UTC)

Fixed wing aircraft

Isn't the transonic operating range only an important operating range for SOME fixed wing aircraft? Namely high speed types such as jets? The introduction makes it sound as if it was important for all fixed wing aircraft, and I doubt it is a big consideration in Cessnas and such..45Colt 08:17, 7 April 2014 (UTC)

Strange thoughts on Area Rule

Such "theoretical" shapes have been found by limited experiment to actually fly. Note that there are total fuselage "holes". A thorough understanding of this subject would incorporate such "anomalies".

http://files.abovetopsecret.com/images/member/9cddcb52914d.jpg — Preceding unsigned comment added by 60.242.247.177 (talk) 00:25, 16 September 2014 (UTC)

Place all questions about speed improvement here

Several members have reverted this page because they do not understand the topic or its effects and do not believe the claims that it doubles speed.

The F-102 was NOT designed with the area rule from the outset, and could only hit Mach 1.1 even with the more powerful J57 on the F-102B. It had to be redesigned into the F-106 also equipped with the J57. The fully area ruled F-106 had twice the top speed of the F-102B with the same engine. They are essentially the same aircraft but the F-106 made full use of the area rule and the F-102 was interim and did not make full use.

The F4D Skyray had the same J57 engine but was completely unable to go supersonic at all because it was not area ruled. The F-106 with proper area ruling was MORE than twice as fast.

For another example, in a non area ruled aircraft the J65 was not supersonic at all. Not a single non area ruled aircraft powered by it was supersonic. But in the area ruled F-104 it was capable of Mach 1.6. Just shy of double the speed.

So yes, it absolutely does double the speed. In some cases its MORE than double the speed.

So please stop vandalizing the page because you do not have knowledge of the subject. — Preceding unsigned comment added by 2600:100E:B02C:A55E:C01F:9C97:54B9:5E0D (talk) 05:27, 13 November 2019 (UTC)

Knowledge of the subject is not a prerequisite for editing. We don't care about an editors expertise or lack thereof. All that is needed is to provide a reliable source for the information. If you are truly the expert you claim to be, then you should have access to such a source. (You're not just making this up out of thin air, are you?) If no source is provided, the info simply gets reverted. Zaereth (talk) 05:52, 13 November 2019 (UTC)

• The F-106 used the J75, not the J57. A third more thrust.

You're also throwing around claims like "twice as fast", but doing so without quoting numbers. And they'd need to be detailed numbers, i.e. are you talking knots vs. Mach and even if you're comparing at the same altitudes, what altitude was that? And just which version of the aircraft and when, because there's also development within the class.

But mostly, you're adding stuff that's unsourced. Please read WP:V and WP:RS. Also WP:BURDEN. Because no-one seems to believe your claims, your claims are so exceptional that they need robust sourcing to stand up, and most of all claiming that they both used the same engine (when you evidently can't even decide which engine that was [1] [2]) is trying to compare apples and oranges.

Oh, and there's also the issue of "doubling" transonic speed meaning a jump up to Mach 1.5 – 2+, which is way off the beam.

The YF-102 went to the YF-102A by adopting area ruling. Its speed went from just below <Mach 1.0 to >Mach 1.2. There were also engine improvements. I don't have better numbers than that to hand. This is significant. It illustrates "the sound barrier" and how hard it was to get fractionally past it. But 20-25% faster isn't "doubling".

Let's call the F-106 the F-102B for a moment. Which will annoy the rivet counters, but hey, it's close enough for jazz. That's an aircraft with a doubling of speed over the YF-102, and it has also adopted area ruling. But it also has a whole different engine in there, with a bunch more thrust. And that's why it's also (nearly) twice as fast as the area-ruled F-102A was. It's faster because it gained a honking great engine, and a bunch of other stuff, not merely from beng area-ruled. Andy Dingley (talk) 17:30, 13 November 2019 (UTC)

Now this makes much more sense. The area rule doesn't cause the aircraft to go any faster; It simply reduces the incredible increase in drag that happens once you hit the sound barrier. It was literally like running into a wall, because the airflow suddenly goes from compressible to incompressible. Quite literally it can't get out of the way fast enough and is compressed into nearly a liquid state. You can see this quite clearly in the photo to the right. I actually took this to a ballistics-expert friend of mine to find out why the mach cone (the shockwave or the so-called Prandtl-Glauert singularity) was not at the end of the bullet where it should be. You can see in the photo the layer of incompressible flow around the bullet as it plows through the air, and the oblique shockwaves that form at the tip. This flow actually extends past the bullet, surrounding a plug of extremely compressed, hot gases that follows the bullet out of the barrel, and it's at the end of this plug that the mach cone forms. (Both flows suddenly become compressible again.) In the photo, which must be just inched from exiting the barrel, the bullet is just breaking the speed of sound, the hot gases are still expanding, and the bullet is still accelerating. The area rule allowed planes to break through this barrier, to slice through the incompressible flow, and allowed the engine to reach its full potential, whatever that may be. I think it would be disingenuous to say it produces a certain, finite increase in speed for all engines in all conditions.Zaereth (talk) 20:35, 13 November 2019 (UTC)