OPNLguy From , joined Dec 1969, posts, RR: Reply 1, posted (10 years 2 weeks 3 days 19 hours ago) and read 2099 times:
>>>Does vapor forming on the wing cause any damage to the wing?
Keep in mind that it's -water- vapor, and the kind in your photo is only there for a short time. If an aircraft can fly in clouds (also water vapor) for extended periods of time, logic dictates that momentary vapor on landling/takeoff is no problem at all, and for that matter, so it flying in clouds for extended periods of time.
Just curious, but why would you think it would cause any damage?
PIA777 From United States of America, joined Dec 2003, 1738 posts, RR: 6 Reply 3, posted (10 years 2 weeks 3 days 15 hours ago) and read 1938 times:
I just thought that it might cause friction on the wing and do some damage, or get inside the wing and short out something. I noticed that when the plane goes through the clouds the engine's change color, from a brownish color to a blueish color. When the plane goes through tthe clouds does the water vapor go into the engine and do something???
Musang From United Kingdom, joined Apr 2001, 793 posts, RR: 7 Reply 4, posted (10 years 2 weeks 3 days 1 hour ago) and read 1850 times:
Just to be nitpicky, If you can see it, its not water vapour any more. WV is an invisible gas, surrounding us at all times to some extent (humidity). If you can see clouds, fog, the stuff in the PIA photo above etc., the WV has condensed, by means of a drop in temperature and/or pressure, into visible moisture. Condensation.
One hears talk of vapour trails from high flying aircraft. It was WV for a split second as it left the engine, and its actually ice crystals, as the condensation of the water vapour in the exhaust has gone through the liquid stage straight to ice, as its probably less than -45 degrees celsius out there. I always thought that was called sublimation, when it goes straight to ice, but I've never heard of "sublimation trails"!
If a aircraft isn't making trails, its not cold enough, or the pressure isn't low enough, but probably the WV content (i.e. the humidity) isn't high enough, but the WV is still there of course.
It doesn't matter to the engine whether its eats the WV in visible form (clouds, fog,) or invisible. Its there just the same.
You'll see more condensation over wings in the morning, when the air's colder. It doesn't take much of a pressure drop to set it off, which of course happens as a matter of course as the wing generates lift. The humidity must be high as well, which is an expression of how close the air is to its maximum WV content. 30% humidity, for example, means the air is holding 30% of the WV it COULD hold for the existing temp. and pressure.
WV is also responsible for the wing tip trails you see, also on cool, humid mornings. The vortices off the wingtips or the outer rear corners of trailing edge flaps, cause the air to suddenly experience a huge pressure drop. The WV again condenses to visible moisture and by definition isn't WV any more, until it eVAPORates back into the air.
Musang From United Kingdom, joined Apr 2001, 793 posts, RR: 7 Reply 8, posted (10 years 2 weeks 2 days 15 hours ago) and read 1758 times:
Aloges! I'm glad you straightened that out, as I wasn't sure. The only dictionary I have is dated 1975 and says, for "sublimate", "Convert from solid state to vapour by heat and allow to solidify again" so I thought it went both ways. Long time since I did High School chemistry!