Talk:Vortex ring

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will try to create a simple diagram soon. this is a pretty hard physical construction to describe verbally. mnemonic 22:52, 2004 Jul 15 (UTC)

woot, finally did the diagram. not sure if i rendered from the best angle...✈ James C. 20:56, 2004 Aug 16 (UTC)

Added a link which includes some graphs showing where a helicopter will enter vortex ring state. I didn't check copyright status, but maybe someone else can see if maybe they ca plot similar graphs or so from scratch at least? Kim Bruning 12:19, 25 Jun 2005 (UTC)

[edit] More general introduction to vortex rings etc.

Hi Guys,

I've tried to add a more general intro to vortex rings and have put the helo-effect as a subheading. I also tried to intuitively explain how the ring may form, but I need some one in the know to check it.

thanksKghose 15:02, 20 October 2005 (UTC)

[edit] Vortex ring / Ground effect in fixed-wing VTOL aircraft

Hi,

While looking into flight test data on an early VTOL aircraft Short SC.1, I came across a research memorandum which refers to the losses in vertical thrust due to what is referred to there as "ground effect". This seemed fine, since this is how I would have described it, so I added the appropriate link to the article. Looking at ground effect however, I discovered that this refers to a net gain in lift experienced by some conventional aircraft wing types when flying close to the ground.

There is a potential confusion here, which I would like to sort out.
Is "vortex ring" specific to rotary wing aircraft?
Is "vortex ring" perhaps the U.S. term, "ground effect" the British term for the same thing?

Here is the reference: Discussion of ground effect w.r.t. the Short SC.1

Thanks TraceyR 19:55, 12 January 2007 (UTC)

Hello Tracey R. The article which you read may have been referring not necessarily to ground effect but of hot gas re-ingestion into the engine. As VTOL aircraft hover close to the ground, hot exhaust gases may be 'sucked' back into the engine intakes which would increase the temperature of the intake air and reduce thrust. Ground effect is an increase in lift that is experienced when an aircraft flies close to the ground, if I recall correctly (been a while since I've flown), within about the distance of a wing span. Oversimplifying the phenomenon, the air underneath the aircraft becomes a 'cushion' that the aircraft rests on increase the net lift. Vortex ring state is as has been described in the article and as far as I know is limited to rotary wing aircraft and is definitely not the same as ground effect or hot gas re-ingestion. Cheers, Angmi —Preceding signed but undated comment was added at 04:37, 20 September 2007 (UTC) Article cited on the SC.1 does not appear to discuss effects of hot gas re-ingestion.--Angmi (talk) 10:23, 13 April 2008 (UTC)