# Hydrodynamic calculations

1. Feb 2, 2014

Hi all,

This is my first post. I was wondering what the effects of hydrodynamics are on water in regards to when you suck water out of a pipe leading to a barrel of water for example. When you then stop sucking the water from the pipe the water leaving the pipe then continues to pull water out of the barrel until the barrel is fully drained.

Firstly what is this effect correctly called? Is this more to do with pressure differential?

Secondly, what are the limitations of this effect? I mean the diameter of the pipe, the original container needs to be higher than the receiving container etc?

This is an interesting phenomenon to me and I would like to learn more about it and hope that you may be able to educate me in this regards or to steer me in the right direction. Finally how would I calculate the velocity of the water leaving the pipe and other similar calculations relating to this effect. Thanks in advance for your assistance.

Kind regards,

2. Feb 2, 2014

### SteamKing

Staff Emeritus
I think you are describing a siphon, but you description is not totally clear to me. The siphon effect works on a difference in pressures between two bodies of liquid.

http://en.wikipedia.org/wiki/Siphon

3. Feb 2, 2014

Wow, that's exactly what I was looking for SteamKing. Thanks!

4. Feb 2, 2014

### SteamKing

Staff Emeritus
You're welcome.