North Pole May Be Ice Free for First Time This Summer

[Mr. Toad]

Originally Posted by RavenTai

the vorticies are generated when the high pressure under the wing tries to cheat and sneak around the wing tip to get at the low pressure above, this is a form of drag the wing is generating pressure but not getting work (lift) out of it, newer aircraft have winglets, they stop the vorticies, decreasing drag, reducing fuel burn and increasing lift,we are adding them to 757's right now,

So there's a current of high pressure air under the wing heading laterally towards the tips? And the winglets stop this? Cool.

[re_guderian]

Thread synopsis so far:

• Global warming will kill us all
• No it won't
• Yes it will
• No it won't
• Yes it will
• Hey, airplanes are cool!

gotta love the MUD attention span. The next version of vbulletin will ask for username, password, and last time you took your Ritalin...

[Rookie2]

Originally Posted by RavenTai

newer aircraft have winglets, they stop the vorticies, decreasing drag, reducing fuel burn and increasing lift,we are adding them to 757's right now,

Seems like I read also since they basically eliminate wing tip vortices, you also eliminate the noise associated with them. Wonder if that's actually perceptable in the cabin. Scott...?

[Rookie2]

Originally Posted by scottm

If I raise the pressure at constant temp, water vapor will condense to steam. If I lower the temp at constant pressure, water vapor will condense to steam. In this case, temp is dropping, but so is pressure. It just seems like the system should stay on the same side of the condensation line, since the two factors should be equally offsetting. Long time since thermodynamics for me.

Me too on the Thermo. I don't think the condesation line is purely linear, so given the fact that atmospheric conditions are very close to the line already, combined with a highly dynamic condition of the wing ripping through the air creating almost a zone of pressure gradient and subsequent temperature change, portions of which are obviously moving onto the condensation curve.

[RavenTai]

Originally Posted by Mr. Toad

So there's a current of high pressure air under the wing heading laterally towards the tips? And the winglets stop this? Cool.

Yes, but not sure I would describe it a lateral flow across the whole wing, just near the tip where there is a readily available path from bottom to top.

another method of dealing with tip vorticies is done on the 767-400 where a flat extension is put on the wing tip that carries it out to a small point, kind of a flat winglet, with only a tiny point to flow around there is little leakage of the under wing air,

note the wing tips, same basic wing but with the tip addition the 400 can generates more lift

767-300



767-400

[scottm]

I don't think you'd be able to hear wingtip noise from the cabin. Flow should be laminar over the wings all the way to the wingtips. All the talk about airplane noise I've heard was due to the engines, I've never heard anything about wings making noise if you keep them subsonic. The cockpit does get noisy, from the wind.

[RavenTai]

At least from the outside, an aircraft on approach, at flight idle, is surprisingly quiet, it can only be heard if there is nothing else going on. mainly engines and maybe a faint whistle of wind noise,


as a passenger if I am seated near the wing you can tell how "dirty" it is (Gear, flaps, spoilers) or cleaned up by sound,

[RavenTai]

Originally Posted by re_guderian

Thread synopsis so far:

• Global warming will kill us all
• No it won't
• Yes it will
• No it won't
• Yes it will
• Hey, airplanes are cool!

gotta love the MUD attention span.

[LukeO]

Originally Posted by re_guderian

Thread synopsis so far:

• Global warming will kill us all
• No it won't
• Yes it will
• No it won't
• Yes it will
• Hey, airplanes are cool!

gotta love the MUD attention span. The next version of vbulletin will ask for username, password, and last time you took your Ritalin...

I can't resist





"Global Warming Beer: Greenland Brews with Melting Ice Cap"


"We already know that climate change is affecting whiskey production in a bad way; happily (sort of) there's now more alcohol being made to offset the loss. A brewery in Greenland is producing beer using water melted from the island's ice cap. They claim that the water is over 2,000 years old, and free of minerals and pollutants, which makes sense considering that it's been locked up as ice and is now springing forth as a result of our warming globe. The beer is made in the first ever Inuit microbrewery, and the whole scenario seems somewhat reminiscent of the old "when life gives you lemons, make lemonade" adage; in this case, perhaps something like "when life gives you global warming, make beer" is more applicable. Those who've tasted the beer claime that the Greenland brew, officially launched in Copenhagen this past Monday, has a softer, cleaner taste than other beers, because of the ice cap water. We aren't crazy about the global-warming profiteering, but if Greenland is going to melt, at least people will be having a good time."



Global Warming Beer: Greenland Brews with Melting Ice Cap : TreeHugger

[OZCAL]

Originally Posted by RavenTai

that is a bad angle for ID between the two but Its a Boeing 727, note it has three engines instead of the Mad Dogs two.

10 years ago I was working 727 Overhaul. was "02 skill" worked the tail, engines and packs.


the vorticies are generated when the high pressure under the wing tries to cheat and sneak around the wing tip to get at the low pressure above, this is a form of drag the wing is generating pressure but not getting work (lift) out of it, newer aircraft have winglets, they stop the vorticies, decreasing drag, reducing fuel burn and increasing lift,we are adding them to 757's right now,

Yes I see no 2 now. Good eye.