>> I sense a Coke can based design aborning.
>
> I was thinking 2l Bottles...


                BCC:  Ken - water motors at end may be of practical interes=
t.

Bottles could be good due to the shape and existing "nozzle".

Cut rectanglarish hole in side of bottle for preceding bottle to pour into.
Angle "lower" bottle so that when in correct position water leaving
the nozzle pours into "higher" bottle.
Exit hole can be made larger by trimming neck.
Exit hole can be angled to present an essentially circular profile in
the exit plane when the bottle is at best exit position.

Should work. Would be "mind boggling" to the uninitiated.

An Archimedes Screw can run backwards as a water motor - the bottle
design could be optimised to accept water into the top bottle from a
nozzle and to "pass it" down successive bottles. This becomes a true
potential energy water motor - such as a water wheel but allows a
small diameter wheel. Speed  for a given power level / flow rate would
be higher than a large diameter "single descent" wheel. MAY even be
practical.

This suggests that a coiled hose water motor may also be useful. Would
be easy to build a test version and MAY even be able to serve
practical purposes. Assuming stiction and friction losses can be kept
to a smallish proportion of power available it would run across a wide
range of power levels as water was available to drive it.

Such motors, or course, for a given efficiency level, can get no more
power from a water head than other turbine types BUT may be more
practical in some head & flow regions. Losses for a discrete bucket
"poured" system come from heat energy caused by kinetic energy
absorbtion (some KE gets used). A true screw system  water motor has
friction and turbulence losses. Would be interesting to see how
efficient a system could be derived.

A large diameter screw (hose pipe wound on drum of much larger
diameter than hose diameter) has a low operating speed per energy and
high torque and MAY be able to be used for eg practical gate openers
or similar. 100 litres falling 2 metres from eg a roof in a rain
shower have 2000 Watt-second of energy. Not very much as a continuous
energy source, but if 50% energy was extractable, that's eg 100 Watts
for 10 seconds. 100 Watts is 10 litre-metres per second - maybe a bit
high for sensible tubing based systems. 10 Watts for 100 seconds =3D 1
litre-metres per second which could be sensibly realised.



            Russell
--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.