We started our experiment by
taking a single container, making a small orifice on its side and filling it
with water. We left it for a short period so as to let the water flow out,
after which we can notice that the water level stops decreasing visibly above
the orifice. This was repeated a few times before we started measuring our
experiments so as to confirm the consistency of the observed phenomena.
Our first line of thought was
that it would be inevitable to investigate some factors, which may affect and
are the foundation of this phenomenon, such as: the size of the orifice and the
container, the shape of the orifice and the container, the position of the
orifice, the density of the liquid, the viscosity of the liquid, the surface
tension of the liquid and Reynolds number for the flow.
Once that was done we agreed
that the measurement of the water level would be done primarily by a ruler, but
to check the accuracy, we took photos where we converted pixels to ‘mm’
and using those somewhat more accurately checked the water level. We repeated
the same process for checking the orifice diameter which was primarily measured
by measuring the diameter of the needles used for making the orifices into the
container. Due to negligible difference between the measurement in both methods
we have adapted the method of measuring the needle diameter and taking that as
the orifice diameter since its significantly faster and less complicated to
accomplish. As for the other factors they were either described in nonnumerical
fashion or referenced from other papers and theory.
A detail that we have noticed
was that when the water stopped flowing a water droplet would form outside the
orifice with a larger diameter than the orifice, it does increase the surface
area, however the amount of water in front of the orifice is small enough that
it is negligible compared to the amount of water held above the orifice so we
have decided to ignore it.
Additionally all following
sketches were authored by and therefore property of Nebojsha Knezhevikj. Any reader can fully use them as they wish,
under no license.
Sketch 1: The start and end of the flow. The end
represents the phenomenon.