Amazing vortex photo

speedbird591 · Post by **speedbird591** » 10 Aug 2006, 12:12

I know many of you will have already seen this on Airliners.net, but in case anyone has missed it it's well worth a look. It illustrates just how much vortex an airliner generates, usually invisibly, and it makes me wonder what the separation distance will be following an A380.

http://www.airliners.net/open.file/1091105/L/

I was once in a 747-236 climbing out of LHR when we flew into the vortices of the 747 ahead of us at about 3000 ft. Normally they would have descended and dissipated in the separation distance, but the winds on this day had kept them aloft. The skipper was hand flying the aircraft when it suddenly rolled hard to port and lost height. As he pulled it back level, the other vortex pulled it hard to starboard. It was a bit worrying and the skipper admitted later that he thought he'd lost it. It was very very close :shock: Scary things - vortices!

DanKH · Post by **DanKH** » 10 Aug 2006, 12:40

Nice find Ian, sometimes reality makes you believe in ghosts...

TobyV · Post by **TobyV** » 10 Aug 2006, 12:42

Excellent flow vis, but to me this suggests that the lack of wingtips on the 777 isnt as justified as Boeing would like to have us believe

speedbird591 · Post by **speedbird591** » 10 Aug 2006, 12:54

TobyV wrote:Excellent flow vis, but to me this suggests that the lack of wingtips on the 777 isnt as justified as Boeing would like to have us believe

What effect do winglets have on the vortex, Toby?

DanKH · Post by **DanKH** » 10 Aug 2006, 12:55

Erhm....they tend to reduce the airflow around the tips..... :roll:

More here: http://www.aero.gla.ac.uk/Research/LowS ... inglet.htm

Here: http://www.airspacemag.com/ASM/Mag/Inde ... /htww.html

Or here:
http://en.wikipedia.org/wiki/Winglet

speedbird591 · Post by **speedbird591** » 10 Aug 2006, 13:03

DanKH wrote:Erhm....they tend to reduce the airflow around the tips..... :roll:

Well how would I know, Dan? We never had no education when I was young! So is a reduced airflow a good thing or a bad thing? Does it reduce the vortex, give more lift, reduce fuel consumption - or what? You can't get away with half an answer - not here!

Ian

Oh - you've just posted lots of stuff for me to read while I was typing! I'll have a look

Thank you.

DanKH · Post by **DanKH** » 10 Aug 2006, 13:17

He, he....I'm well ahead of you, I saw that comment coming..

speedbird591 · Post by **speedbird591** » 10 Aug 2006, 13:20

DanKH wrote:He, he....I'm well ahead of you, I saw that comment coming..

Well, watch out here comes another one!

If winglets were any good, wouldn't they have been invented by the British in 1953?

DanKH · Post by **DanKH** » 10 Aug 2006, 13:22

A VC10 with Winglets... !...I'm speechless.... :roll:

DanKH · Post by **DanKH** » 10 Aug 2006, 13:25

Btw...try: http://oea.larc.nasa.gov/PAIS/Concept2R ... glets.html and do a search on "england" 1897 .... but apprently not used on the VC10 ;-)