[NewCandle] Aeolian harp update

[Keith Nagel]

Hi John + all,

Thanks for the update. I think the "variant forms" idea has
some merit, it's a simple solution and one can imagine an
that an ideal form might exist that works over a broad
range of wind speeds. In fact, a body of work exists that
mirrors this idea, in the form of broad band antenna designs.

For myself, I am also dipping into the antenna oeuvre for
some ideas, but more about that later as I would like to
do a few simple experiments first to see what's possible.
My "antenna" design however will still be a basic cylindrical
cross section wire. Using structures with appreciable
surface area will suffer from the same problem that Jones
wrote about with his pipe organ, that is loss of energy
to sound wave emission. Jones story made me chuckle;
when I lived in Brooklyn the sound levels outside were
so intense that the windows in the back of the brownstone
would shake regularly. It amazes me that there still exist
people that appreciate a little peace and quiet. I really
still think that everyone around me is deaf sometimes.

Nick mentioned ion collection. This idea just _reeks_ of
my old friend Fred Sparber. He and I have both done experiments
on this. For myself, I did them in the early 90's using
large surface area elevated metal sheets and mechanical
relays shorting the plates to ground. As Nick reports,
the results were less than stellar. If you think about
it Nick, this is the field mill writ large.

BTW, I tried to call Fred last night, and my number no
longer works for him. Anyone know what's up? Last time
I talked to him he was doing another round of chemo I think,
and he sounded pretty grim. He's about due for another call
to set his mind free for a bit. Digits anyone? Horace?

K.

-----Original Message-----
From: newcandle-bounces at ipdiscover.com
[mailto:newcandle-bounces at ipdiscover.com]On Behalf Of John Steck
Sent: Monday, November 03, 2008 7:56 PM
To: New energy for the new world.
Subject: Re: [NewCandle] Aeolian harp update


Cool.  Thanks for spending the time digging around for more info.

The wind speed thing was something that I recognized right away as a
fundamental stumbling point.  I have been looking at a couple of mid-string
forms to possibly make best use of any given wind speed.

If I can get it to flutter just right, I might be able to create the
necessary change in moment to drive the cantilever in the existing device
without much/any modification/customization.

I anticipate such a device will generate a sound very much like that loose
piece of vinyl siding in a wind storm right outside my bedroom window... 8^)

-john


--------------------------------------------------
From: "Keith Nagel" <NewCandleAdmin at ipdiscover.com>
Sent: Monday, November 03, 2008 1:53 PM
To: "New energy for the new world." <newcandle at ipdiscover.com>
Subject: [NewCandle] Aeolian harp update

> Hi All,
>
> Just a quick update on things aeolian, before I get back to hackin's.
>
> The frequency of vibration is ~ (1/5 * Windspeed) / wire diameter
>
> A simple single string will therefore only work at certain quantized
> wind speeds. The length of wire would have to be resonant based on the
> speed of sound through the wire and the spacial harmonic you are
> looking to excite ( probably half wave mode for this application ).
> A harp is a plurality of such strings, each of a different diameter
> and length to allow for sounding over a range of wind speeds. This
> is not the best way for us to go, but it should suggest to you
> some of the challenges to a usable industrial design.
>
> I found a musician on the net who did some simple experiments with
> wire and wood sounding boards, check out some of the videos here.
>
> http://www.youtube.com/profile?user=lukejerram&view=videos
>
> The tent/plywood sheet system is very clever, and must have made
> for an interesting sound installation piece. You can also see
> what I was saying about the need for a sounding system if you
> want appreciable sound to come out. I think that a power system
> would be fairly quiet in practice because we would be damping
> the oscillations by drawing power and the only coupling to
> the air is through the wire itself ( for example, go to
> the music store and pluck an acoustic guitar string, then
> try same on an unamplified electric guitar. )
>
> K.
>
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