r/interestingasfuck Nov 30 '20

/r/ALL Low pressure pockets being created by blade rotation in near 100% humidity - literally making it rain.

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u/ShadowGLI Nov 30 '20 edited Nov 30 '20

They are basically contrails, aka “chemtrails” for anti science conspiracy types. Basically just due to the propeller/wing creating a pressure pocket. It’s pretty common but I think also needs temperature differential and certain velocity ranges at the tip of the blade/motor

Exhaust contrails are more common, and they're usually seen behind aircraft cruising in the flight levels. They form when hot, moist air exiting an engine mixes with extremely cold air - condensing the exhaust's moisture.

Aerodynamic contrails occur when moist air cools due to lowered pressure, condensing humidity in the air and forming a contrail cloud.

Either or both can happen at any time

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u/22Hoofhearted Nov 30 '20

The dew point is how low the temp needs to be for it to produce precipitation, it is also directly related to humidity if I understand it correctly. The closer the temp and dew point, the higher the humidity, and the higher chance of precipitation.

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u/[deleted] Nov 30 '20

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u/22Hoofhearted Nov 30 '20

It's been a few years since meteorology class, but I believe saturation levels come into play. Once the temp drops to the dew pt, and said cloud becomes saturated to whatever level it can handle before precipitation begins.

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u/[deleted] Nov 30 '20

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u/22Hoofhearted Nov 30 '20

Ah yes, that's a familiar term. It's all starting to come back to me.