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What makes the vapor over a wing?

Discussion in 'Technical Talk' started by turbojet28, Jul 23, 2004.

  1. turbojet28

    turbojet28 Well-Known Member

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    Hey everyone,

    Just a quick question; many times you can see when an aircraft is taking off (and seen a lot on fighter jets when they do very steep/tight turns - sorry for the "non-technical" way of describing it /ubbthreads/images/graemlins/smile.gif ), there is condensation above the wing and off of the wingtips (almost in the vorticies). What exactly makes this? If I had to take an educated guess, it seems that it usually happens in flight conditions at high angles of attack (such as takeoff or tight turns while holding altitude), so my thoughts were that it is from Bernoulli's Law and when these high angles of attack are made at high speeds, the pressure lowers enogh to allow the air to cool to saturation and condensation. Is this correct? Thanks!

    P.S. - I would just "google" the subject, but its more fun to discuss it here! /ubbthreads/images/graemlins/cool.gif
  2. cime_sp

    cime_sp Well-Known Member

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    Correct. They are called contrails and are nothing more than condensed water vapor. The wing is creating it's most lift during takeoff or like you said during maneuvering flight and this causes a drop in pressure. That drop in pressure causes the air to cool and water vapor in the air to condense.
  3. Ralgha

    Ralgha Well-Known Member

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    Actually they're chemtrails, and they consist of various chemicals that we spray over the population to further government experiments and population control programs.

    We also have dark beam weapons that shoot out the front, but I'm not supposed to talk about those.

    Actually, you probably better forget you read this altogether.
  4. aloft

    aloft Suspended

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    You are correct, sir. The same principle is at work in the formation of upslope fog and standing lenticular clouds.

    <--actually learned something from my IR Gleim book! /ubbthreads/images/graemlins/grin.gif
  5. aloft

    aloft Suspended

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    [ QUOTE ]
    Actually, you probably better forget you read this altogether.

    [/ QUOTE ]

    Just stare at this light for a moment....*flash*
  6. kellwolf

    kellwolf Deadbeat

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    [ QUOTE ]
    <--actually learned something from my IR Gleim book!

    [/ QUOTE ]

    Snoop Dogg has an IR?!??! Who knew. /ubbthreads/images/graemlins/smile.gif
  7. FalconCapt

    FalconCapt Suspended

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    [ QUOTE ]
    my thoughts were that it is from Bernoulli's Law and when these high angles of attack are made at high speeds, the pressure lowers enogh to allow the air to cool to saturation and condensation. Is this correct?

    [/ QUOTE ]

    Exactly correct...
  8. PhilosopherPilot

    PhilosopherPilot Well-Known Member

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    [ QUOTE ]
    Correct. They are called contrails and are nothing more than condensed water vapor. The wing is creating it's most lift during takeoff or like you said during maneuvering flight and this causes a drop in pressure. That drop in pressure causes the air to cool and water vapor in the air to condense.

    [/ QUOTE ]

    I thought contrails were the result of the jet exhaust at high altitudes. Does this term also apply to the situation described above?

    G
  9. mtsu_av8er

    mtsu_av8er Well-Known Member

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    Contrail=condensation trail. The difference is the manner in which they are produced.

    When they form on the wing as a result of pressure differentials, they're called aerodynamic contrails.
  10. cargopusher

    cargopusher New Member

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    Is this the same as 'putting on the sweater"?

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