Physics: - - - - Gravity Powered, Liquid Surface Tension Engine.


In a sealed container of liquid, a capillary tube raises the surface up against gravity.
At the point where the new surface come to rest, a wick is connected and hangs down.
The liquid soaks into the wick, it then flows down because of gravity back into the container...

The Wick's drop must be long enought so that the liquid soaking in from on top weighs more than the
liquid soaking up from below. If it is to short it will equalize and not flow down.

When assembling; Use rubbing alcohol, or crud will grow and clog a water version.
To attach the wick to the tube, use a fine wire tied to the wick, run the wire through the tube
to the bottom and bend it back. Its best to do it under the surface of the liquid so the wick is
soaked with the liquid and there are no air bubbles in the tube with the wire.

Capillary Force or SurfaceTension lift, the liquid up against gravity, so it is available to fall again...



Update 8-25-00


Its very simple;

Capillary action creates a new, elevated surface, above the main surface.

The new surface defies gravity, because it is stable at a height
greater than the surface from which the capillary tube extends.

If water evaporates or is absorbed from the new surface the cap-action
will, maintain the new surface level, at the same height above the main surface.

What happens to the liquid removed really doesn't have any effect on the
new surface level caused buy the cap-action it is dependant on the cap
tube diameter and fluid dynamics. Unless, enough is removed to lower the
new surface to a point below the wick connection breaking the flow.

I suppose that the wicking away of the water is another cap-action
like effect, the string looks as if it has a surface around it when this is
working/flowing. (Sort of full/very-wet look)

The water on/in the wick is under influence of gravity and will fall if allowed to.

The wick hangs down,, the water falls.

Back at the top the wick is still absorbing liquid from the upper surface.

The string hangs down into the main surface, making surface tension contact.
There is no surface tension to break as there would be if it had to Drip...

Iv built 5 or more they did not all work at first but all worked eventually,
And the one on the shelf is still working, but I think the level is getting
Lower because of evaporation thru the baby food jar top. (Bad seal)

The .gif video on my web site ran for about 5 days before alga clogged
the connection at the top of the cap tube. It was made in a baby food
jar and assembled under water in a large bowl of Water.

When I added the food coloring the food coloring displaced the water in/on
the string and it flowed back for a few minuets before normal flow resumed.

When I watch the full framed video .avi at 15fps, I can see the flow
slow after a day or so and it stopped sometime after the 5th day.

Since then, I have built others using alcohol and ink, ink is more like a
paste it sits on top and melts into the flow below it. Someday I may
rerecord, one washing all of the ink away into the liquid and then lightly
staining everything.

But im lucky to make it a few days before this computer will crash for
one reason or another, killing the photo session. Starting over is easier
said than done. Ill get it someday...

The photo setup is in a square cardboard box laying on its side with a
long rectangle cut in the top where a 1" diameter florescent light was
shining in, on the open side the camcorder was pointed in, and covered
up with black trash bag material. I did peak in from time to time by
moving the trash bag aside a bit and returning it when done.

The video capture software was setup to grab a frame every hour and
assemble them into a time lapse .avi 8mb.

The light was on all the time.