Talk:Propeller

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Contents

[edit] Additions requested

Sirs,
A very good article on propellors but two additions should be made to this page.

  1. Reversable propellors ( to brake the aircraft ) were developed after the Second World War
  2. Early variable-pitch propellors had only two settings, fine for take off and coarse for cruise, and had to be "set" on the ground (with air pressure) and could only move to course once by pilot control. —Preceding unsigned comment added by 216.192.158.129 (talk) 07:15, 8 January 2004
Should the Harvard trainer be mentioned somewhere? The tips of the propeller were supersonic, which made for a great deal of noise, especially to an observer in the plane [pun unintentional!] of the propeller disc. 81.130.91.115 09:52, 16 July 2007 (UTC)

Hmmm. There's a whole lot about aircraft propellers and not much about ships/submarines.

Nojer2 18:45, 19 Feb 2004 (UTC)

Feel free to add to it! which I notice you're doing. —Morven 19:05, 19 Feb 2004 (UTC)

[edit] Re-write/re-organization needed?

This page is a mess, with a lot of general propeller info in the airplane section, a lot of of historical info in the ship/sub section, and a mish-mash of more and less technical parts. I made a quick pass at improving the introductory paragraph, but could use some help or suggestions to improve the rest of the page in a coherent way.

knotnic 00:15, 7 Aug 2005 (UTC)

A horrible mess, the history section for starters. Archimedes' screw is in no way related to the propeller, nor are sculling, windmills or even the turbine related to the development of the propeller.Jmackaerospace 01:50, 6 September 2006 (UTC)


THIS ARTICLE IS TOTALLY BIAS. THERE IS NOT ONE NEUTRAL OR BALANCED WORD IN THIS ARTICLE. SOMEONE SHOULD LEARN SOME DIPLOMACY. —Preceding unsigned comment added by 130.113.32.136 (talk)

[edit] Screwed?

The ship's propellor was also affected by the ability to move machinery lower in the hull, which was a factor in naval battle damage. The variable-pitch airscrew is credited to several people; let me pitch for Canadian Wallace R. Turnbull, 7 Feb 1922, at Rothesay, NB. And another Canadian, John Patch (Yarmouth, NS), in 1833 invented a paddle/oar, & in 1849 a double-acting variant that was more efficient than contemporary screws. Trekphiler 05:22, 8 December 2005 (UTC)

[edit] "Propellor Walk"

I am thinking that this segment needs to be shortened and simply pointed to the article it refers to. The more I look at it the more it feel out of place. It is more "Seamanship" than a technical item on propellers. I'll think some more and do this in a while. Fiddle Faddle 10:38, 2 May 2006 (UTC)

It is well covered in its own article. Moved to "see also" as a link. Another small step towards clarity Fiddle Faddle 19:57, 8 May 2006 (UTC)

[edit] "Wing-axis prop"

I have been looking everywhere for an article on experimental lateral-axis (wing-axis) props. I saw a prototype which had a prop inside the leading edge of the wing, and worked by pushing air over the top of the wing along the wing's length. This system provides lift with zero airspeed, but flies like an airplane. This system shows promise as a VTOL propulsion system, or as part of a "flying car," so is significant.

What you're talking about is, like a vertical axis wind turbine,cyclogyro/cyclocopter ,fanwing, or the Voith-Schneider propeller pic on the article page.. there's a lot of confusion with those types, in all fields they should be called transverse axis- acros the flow, insted of calling is something new making it harder to draw these connections... Also notice that the fanwing is just producing [magnus effect|magnus lift] and that a variable pitch blade on a cyclo-thing really just amounts to flapping like a bird/bug/bat. --Sukisuki 20:44, 27 October 2006 (UTC)

[edit] Cavitation Damage

I've added an image of the type of damage that can occur to a propeller operating under cavitating regime. Axda0002 23:03, 20 May 2006 (UTC)

[edit] "Aeroplane"

I really do say! "Aeroplane" is not "weird" - it is British! --Profero 18:25, 1 June 2006 (UTC)

"Don't call me Shirley." Trekphiler 12:31, 6 October 2006 (UTC)

Hey! It's not just British. I'm Aussie and I say "aeroplane" too. Dr algorythm 09:12, 9 June 2007 (UTC)

[edit] Unscrewed

I deleted this:

"Submariners call the propellers on submarines 'screws'."

It's not limited to sub sailors; navy men around the world do in reference to ship propellors; sonar operators shipboard, heliborne, or submarine will report "screw noise". My problem was how to phrase it; "navy men" seems awkward, "professional sailors" seems to imply civilians aren't. Anybody that can come up with a better way, please rewrite & restore. Trekphiler 12:31, 6 October 2006 (UTC)

... and it's not just the military: TSDY translates to Twin Screw Diesel Yacht. 81.130.91.115 09:52, 16 July 2007 (UTC)

[edit] Axial speed vs Rotational speed

What's the difference? I know Rotational speed must be RPM; So is axial speed the distance WRT time that a point on the prop covers? Am I the only layman where this required significant contemplation of these terms? :-) —The preceding unsigned comment was added by 59.167.221.55 (talk) 17:34, 10 December 2006 (UTC).

[edit] "Feathered position" and "Feathering"

If anyone gets around too revising the section on aviation, it would be great to include a sentence or two about "feathering". I came across a reference to this in the article on the Bay of Pigs Invasion of all places, and was curious about what it meant. The best I could do was find a brief sentence in the disambiguation page for feather. I came to this page and found it mentioned in the caption to the picture of the Hercules props in the aviation section. But the associated text makes no mention of what feathering or the feathered position for props actually is! Dr algorythm 09:12, 9 June 2007 (UTC)

How did we miss that. Photo and text added. Meggar 16:28, 9 June 2007 (UTC)

[edit] Sculling

The mention of single-oar sculling in the History section should be explained or qualified. Doesn't this method of propulsion rely mostly on vortex shedding, similar to the way insects such as bumblebees produce lift? The modern aircraft propeller or ship's screw is actually a rotary wing, and produces lift in accordance with Bernoulli's principle. —QuicksilverT @ 19:28, 14 August 2007 (UTC)

As someone who single oar sculls, the vortexes seem to be coincidental. Motive force is created by the sweep slicing through the water at an angle, but being held firm by the sculler. Force is transmitted via the sculling notch which drives the boat forward with a much simpler seeming leverage action. Creation of vortices seems to reduce the efficiency of the stroke. This is very similar to, but the opposite of, the draw stroke, used by canoeists and coracle users, the formerto create sideways movement, and the latter to create any movement in the desired direction. Fiddle Faddle 22:15, 30 October 2007 (UTC)

[edit] Uses

There needs to be a section on the uses of propellers in aviation. To my understanding, they are used for small planes and huge planes. The article should mention that (if it is true), and explain why. My uneducated guess is that propellers provide greater efficiency but lower speed than jet engines. Whatever the answer, it should be included. Twilight Realm 22:04, 30 October 2007 (UTC)

I don't think there is a size of plane that is inappropriate for a propellor, so I am not wholly sure what direction your thoughts are heading in? If you can clarify somewhat that would help a little more. Fiddle Faddle 22:10, 30 October 2007 (UTC)
Small personal planes have props. Commercial planes have jet engines. Gigantic planes meant for transporting heavy cargo use propellors. Am I right? If so, why? Twilight Realm (talk) 01:39, 27 November 2007 (UTC)

[edit] Hovercraft, not helicopter

I have looked at the "helicopter" Leonardo Da Vinci invented and it works the same way as a hovercraft, using fan(s) to push air downwards. 122.105.218.141 (talk) 00:28, 24 January 2008 (UTC)

[edit] Efficiency of marine propellers

Unlike the aircraft section, that on marine propellers give lots of formulae for calculating efficiency - IMHO too much given the likely readership - but no actual number for a typical modern propeller.

JamesWim (talk) 18:25, 1 February 2008 (UTC)

[edit] Request equation cleanup

I'm interested in the section beginning with "Forces acting on an aerofoil", but it's a bit confusing.

Preceding the equation, variables F, A, V, c, and alpha are explained.

The equation, then, introduces f, rho, and Rn, but doesn't use c.

Rho, f, and Rn are not explained in proximity to the equation. Presumably, Rn is Reynold's number, and uppercase C is a coefficient, but lower case c doesn't appear anywhere I can see.

Ve3wtj (talk) 00:01, 20 April 2008 (UTC)