Talk:Contra-rotating propellers

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Contents 1 Tandem rotor helicopters 2 Turbulence between props 3 F-35B lift fans 4 Contra-rotating vs. counter-rotating

[edit] Tandem rotor helicopters

Question : should this page include examples of and discuss tandem rotor helicopters? To me these are two different but similiar things : propellers give thrust to a fixed wing aircraft ( or whatever ) and tandem rotor are a special type of helicopter. 145.253.108.22 10:11, 11 January 2007 (UTC)

I don't think tandem rotors should be discussed here because they are counter-rotating, not contra-rotating; the article explains the difference. In fact, barring objection in the next few days, I'll remove the reference to the tandem rotor helicopters (unless I forget). Quickfoot 22:39, 23 February 2007 (UTC)

[edit] Turbulence between props

I'm no expert in contra-rotation but wouldn't there be a small loss of efficiency caused by the second prop biting into the turbulent stream of the first prop? If so, it's worth a brief mention. Binksternet (talk) 17:23, 20 November 2007 (UTC)

[edit] F-35B lift fans

Isn't it worth mentioning that the F-35B lift fans use this principle? The current version of the article about the F-35 Lightning II links here. --RenniePet (talk) 13:28, 25 November 2007 (UTC)

No. They are not propellers. The link needs to be changed/removed. - BillCJ (talk) 17:21, 25 November 2007 (UTC)

Hmm. Well, I've looked a bit more into it, and the F-35 page has had a link to "contra-rotating" for at least a year (can't be bothered going back farther). "Contra-rotating" is a redirect page, redirecting to this page, and has been that since it was created in 2004.

There should be something informative on Wikipedia about contra-rotating in general - I must admit I'd never heard of the concept before seeing it on the F-35 article. Are you suggesting that the "contra-rotating" redirect page should be changed to a stub article, or a disambiguation page? --RenniePet (talk) 18:15, 25 November 2007 (UTC)

Changing it to a stub or DAB page is probably the way to go. We could add some of the info on helicopters and marine screws to the stub as a start, along with a brief summary from this page's current content. Good idea! Thanks. - BillCJ (talk) 18:40, 25 November 2007 (UTC)

Well, I've made a first attempt at it. See Contra-rotating. Please edit it as you think applicable. --RenniePet (talk) 17:26, 26 November 2007 (UTC)

[edit] Contra-rotating vs. counter-rotating

As a naval architect and as a foreigner I'm a little bit confused: As everybody can verify with Google, in the context of ship propulsion many people call this principle counter-rotating rather than contra-rotating, and I remember that I've never heared or read contra-rotating till now. On the other hand, the counter-rotating property of twin propellers doesn't need its own term in naval architecture, because it's nearly always the case (one right turning and one left turning ship propeller). As a foreigner, I'm not going to teach English to the native speakers, but I didn't want to leave this unmentioned, and I would like to encourage not only engineers of avionics, but also naval architects to confirm that Wikipedia is right and that it's wrong to call two ship propellers concentrically rotating about a common axis "counter-rotating". Henning (talk) 13:00, 28 April 2008 (UTC)