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what makes some teapots dribble ? the solution

updated fri 2 dec 11


ivor and olive lewis on thu 1 dec 11

Paul Haigh would be correct to cite the work of Bernoulli. The principle is
akin to that of the Venturi where pressure changes happen to any fluid,
liquid or gas that flows through a conduit of changing cross sectional area=

There are assumptions made, one being that the density remains constant and
the rate of flow, in terms of volume per unit of time remains constant.

If my understanding is correct this means that if the area of the conduit i=
halved the velocity doubles, and if the area is reduced to a quarter the
stream will flow eight times as fast.

So, by having a well tapered spout and an adequate number of holes in the
strainer, giving a large surface area in comparison to the area of the
orifice of the spout, the emerging stream has sufficient energy to keep it
flowing through the air without turning into a spray. Then, as your right
the pot and stop pouring the last of the tea to leave the spout flies into
your cup.


Ivor Lewis,
South Australia