telophase: (Near - que?)
telophase ([personal profile] telophase) wrote2011-12-08 11:05 am

Huh

So I've got that little travel humidifier running in my office. I also have a fan on, because the water vapor mostly falls down to the ground and makes me feel like it's just getting the carpet wet (it vanishes into the air a foot away from the humidifier; it's probably fine), but with teh fan on I get a vague sense that it's blowing into the air. :D

Something I noticed though - the fan is turned away from me because my hair blowing around annoys the fool out of me. The humidifier is offset from it, not in the direct airstream but next to it, and the water vapor coming from the thing gets pulled sideways and back before getting into the airstream. Huh.

Can anyone tell me the physics of this? I assume there's an area of low pressure alongside the stream of air from the fan, which pulls the water vapor in?



The top two pics are with the fan on, one from the front and one from the top where you can better see the water vapor being pulled into the airstream. The last picture is one when the fan is not on, so you can see what the vapor normally does.

Pic on imgur

P.S. The stains on the desk are water stains, caused before I realized that some amount of the water vapor condensed on the unit and ran down to puddle underneath it. Hence the paper towel it's sitting on now. Although since I started using the fan with it, I haven't had that problem.

[identity profile] inkblot14.livejournal.com 2011-12-08 08:24 pm (UTC)(link)
I remember this from Mr. Wizard. Bernoulli's Principle. It's the same basic idea behind perfume atomizers. The fast moving air across the opening of the mister draws the water vapor out into the stream and helps disperse it.

[identity profile] telophase.livejournal.com 2011-12-08 08:42 pm (UTC)(link)
Thanks!