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XyZspineZyX
06-22-2003, 04:21 PM
Why is there contrails when you pull a stall? Just a Q i've been wondering about for a while

XyZspineZyX
06-22-2003, 04:21 PM
Why is there contrails when you pull a stall? Just a Q i've been wondering about for a while

XyZspineZyX
06-22-2003, 04:45 PM
Hello,

Condensation trails, commonly called contrails, are narrow cirrus cloud streamers that form behind high flying aircraft. Contrails are formed by two basic processes. The first method of formation relies on hot and humid engine exhaust mixing with air of low vapor pressure at low temperatures. As the added moisture and particulate matter from the exhaust mixes with the cold air, condensation occurs and the streamer is born. These types of contrails are sometimes called exhaust trails.

The second method of formation occurs when an airplane flies through air that is clear but has a relative humidity near 100 percent. The pressure change generated by the air flow over the wing tip causes a reduction in temperature and results in complete saturation of the air. The turbulent vortex generated by the wing tip completes the process and a contrail is generated behind the wing tips. These contrails are not as pronounced as those formed by engine exhaust and are comparatively rare. Contrails formed by this process are sometimes called aerodynamic trails.

Under the right conditions contrails can persist for a prolonged period of time and sometimes evolve into a complete layer of cirrus.

Cheers,
IO


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XyZspineZyX
06-22-2003, 05:39 PM
and the wingtip vortices become stronger at high AOA, which is why you see these contrails in a stall or tight turns.

XyZspineZyX
06-22-2003, 05:48 PM
Thanks for the quick replies http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif

ShadowHawk__
06-22-2003, 05:50 PM
Higher AOA generally means more lift, as lift is created by lower pressure above the wing, the higher the lift the lower the pressure. The lower the pressure the less dense the air and equal amounts of moisture, eventually the air gets thin to the point of being saturated and water vapor is released in the form of a contrail.

-Death From Above

XyZspineZyX
06-22-2003, 06:07 PM
looking for tip contrails on your enemy when you dogfighting can be very helpful in judging how hard hes turning and what his energy state is

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XyZspineZyX
06-22-2003, 06:12 PM
Fennec and Shadowhawk,

Still remember this from your PPL course, huh? /i/smilies/16x16_smiley-happy.gif

Cheers,
IO


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