Shower curtain movement?

[blike]

Alright, I got in the shower this morning, and I noticed something interesting. Whenever I turn the shower on, the shower curtain is pushed toward the water. At first I thought maybe it was because the air conditioning vent behind it was blowing it in, but then I realized there was no air conditioning vent in the bathroom. Also, when I turn the water off, the shower curtain returns to its normal position.

Anyone else experienced this? What causes it?

[Brad]

There was an article in Discover or Scientific American not too long ago. I believe the motion is caused by the vortex caused by the hot water cooling off on its way down. This cooling warms the air and causes swirling and movement. It is kind of like a weak mini-tornado.

[Hogslayer]

A vortex? You mean like a spinning vortex?

You mean the spinning vortex is pushing the curtain into it?

Spin gravity?

LOL!

I've always been fascinated by this myself. That cooling effect does not quite cut it, IMO, based on some "experiments" if you could call it that. Hot water, cold water, different shower heads. Yes, it definitely indicates an easily distracted mind :D

Here is my theory. Chop it up for me if you can, that's what its all about:

There is a massive volume of vaporization taking place.

Higher humidity creates less dense air.

The pressure of the lower humidity air on the outside of the curtain pushes it in.

[Radical Edward]

aah but then the air has to go somewhere. I think it is just the warmer air rising over the top of the curtain, and the cooler air just pushing the curtain out the way in order to replace all the warm air that has just left.

[Hogslayer]

Try it with cold water.

[Radical Edward]

you'll have to tell me if that works, this shower curtain is far too wrinkled to have any effect

[blike]

Originally posted by Hogslayer
Here is my theory. Chop it up for me if you can, that's what its all about:

There is a massive volume of vaporization taking place.

Higher humidity creates less dense air.

The pressure of the lower humidity air on the outside of the curtain pushes it in.

Well, I have 2 layers of curtains. One extends into the tub, and the other extends out. Only the one on the inside is sucked in. The outside is not "pushed" in. I'll try with cold water in a few minutes.

[blike]

By the way, I just tried it with cold water, and the curtain is still sucked in.

[Radical Edward]

induced charge maybe? though that could be wrong....

to see what I mean, try rubbing a comb through your hair, and then putting it next to a running tap (not running too quickly, or you will drown out the effects)

[Hogslayer]

Okay, some re-evaluation is in order.

Water temp is not a factor (I have observed this much).

I am assuming you have a thick plastic inside sheet and a porous sheer outside (help me if I'm wrong).

Disprove me by reversing the curtain. I only have a single plastic curtain.

[fafalone]

It moves because of the Bernoulli effect which is perpetuated by the continuous flow of air from the shower head. This creates a pressure differential, causing the curtain to move.

[Ragnarak]

Isn't this the same thing as the ping-pong ball on a string being 'sucked' in towards the running tap which we all played with as kids at school during science class?

[blike]

Isn't this the same thing as the ping-pong ball on a string being 'sucked' in towards the running tap which we all played with as kids at school during science class?

I must have been absent that day :) :embarass:

[Tom Mattson]

It happens because of the Bernoulli effect.

The air moving past the curtain is faster inside the shower, thanks to the falling water. Bernoulli says that if the airspeed over one surface is greater, then the air pressure must decrease. Thus, the pressure on the outside of the curtain is greater than on the inside, and the curtain is pushed in.

It's the exact same reason that airplanes fly.

Tom

[blike]

Thanks tom :D

[JoeDaWolf]

http://www.sciam.com/askexpert_question.cfm?articleID=0003302E-388B-1C71-84A9809EC588EF21&catID=3&topicID=13

When the simulation was complete, it showed that the spray drove a vortex. The center of this vortex—much like the center of a cyclone—is a low-pressure region. This low-pressure region is what pulls the shower curtain in. The vortex rotates around an axis that is perpendicular to the shower curtain. It is a bit like a sideways dust devil. But unlike a dust devil, this vortex doesn't die out because it is driven continuously by the shower.

[Dudde]

But the Bernoulli effect is based on a balance between pressure forces and acceleration, and does not allow for the presence of droplets
well no...we didn't say water droplets...I do believe the conclusion was that the droplets accelerated the air?O_o

I feel sorry for any and all of you who tried the cold shower thing;)

[matter]

That has happened to me. I was not curious enough to wonder why it was happening though, it just annoyed me because it kept touching my leg and I was like "WHAT THE FUDGE"

[alt_f13]

Wow, is there anything a shower cant teach you?

[JaKiri]

Calculus