T Nation

Liquid Through Small Hole

Been searching google for a while and can not seem to get an answer.

How would you remove liquid through a small hole fast?

uh…suck harder?


Apply pressure to another orifice that is a tap into the same control volume that you intend to remove the liquid.


How small are we talking? Your basic issue is you need to provide a way for air to get into the area which is currently occupied by water. That will significantly increase thr rate at which the water comes out.

If you can swirl the thing that has a hole in it, it will come out far quicker (unless we’re talking keyhole size here). Try it with a bottle of water as a proof of concept.

3/16 inch hole in glass spheres. No other holes can be made.

Stick a straw in the 3/16’s hole so that it extends past the water level. Thereby allowing air to replace the water.

How viscous is the liquid? Can a super wet type of fluid be used?

edit: Or maybe use heat so that the gas behind the liquid expands and pushes it out?

The liquid is water.

Boil it so it leaves under pressure as steam.

Decrease the pressure outside the sphere. Put it in a vacuum of some type or blow air across the opening.

Can you make the small hole into a bigger hole… Id just use a pump.

Adding a small straw to allow air into the top of the sphere is a good idea. This will allow air to flow in and water to flow out simultaneously. You may need to work to find a straw small enough. Another option to fulfill the same purpose would be a glass capillary tube.

If the sphere is completely full you will need to first drain some of the liquid. Then you need to get the straw through the water without it filling with water. So you’ll need to cap the end of the straw to trap in air and push it through the water. Then uncap the end and it should allow air to go in while water goes out.

The problem you will run into is that the holes are so small that the surface tension of the water will greatly hinder the flow. Adding a small amount of a surfactant, such as a detergent, will significantly reduce the surface tension of the water, allowing it to flow more freely through the small opening. Combine that with the straw and it should work well.