[ExI] underwater sprinkler, was: RE: Musical instruments in space

[spike]

>... On Behalf Of BillK
Subject: Re: [ExI] underwater sprinkler, was: RE: Musical instruments in
space

On Sun, Mar 31, 2013 at 10:05 PM, spike wrote:
<snip>
>>... I have tried to derive those equations, and I have failed so far.  But

> if you manage to derive the equations of motion, I can show you how to 
> solve them and make a controls system.  Then we can rig up a 
> physical-world analog, test it to see if we know what we are doing, or if
we are just a
> bunch of controls wannabes.  {8^D   If someone here manages the derivation
> and it turns out simple, I will be highly annoyed.  But I will get over
it.

>...<https://en.wikipedia.org/wiki/Feynman_sprinkler>
Quote:
>...The smallness of the torque on a reverse sprinkler is closely analogous
to the propulsion of the so-called "pop pop boat," a toy boat that moves
forward as it alternately expels and then sucks in water through a pipe
connected to a small internal tank heated by a candle...BillK
_______________________________________________


Ja.  But give us equations, me lad.  We cannot solve sentences and
paragraphs, we cannot derive a control system from it.  If we do this right,
we could play a song with that underwater sprinkler.  It would be a fun
accomplishment.  We could show it to the controls grad students and ask
them: can you do this?

spike