Re: mermaids' string?

On 15 Jan 2006 16:24:47 -0800, Estrelda wrote:

> Bill Swears wrote:
>> Woodwinds only work in air because we build them to do so. I wonder if
>> you couldn't get a similar sort of vibration from a different size of
>> reed, if your intent was to produce sounds audible underwater.
>>
>> Bill
>
> That's what I was wondering. My knowledge of physics is pretty
> limited, but my understanding of woodwinds is that sound is produced
> because pushing the air through the pipe produces waves. Waves require
> something fluid to exist (whether that fluid be liquid or gas),
> therefore, it seems logical to me that you could set up something like
> it in water. But would the results be audible? Audible to human ears,
> or on some kind of frequency that human ears couldn't detect? And
> would the results be worth listening to? And by whom?
>
> Estrelda.

The whistle principle would work, and in water, with higher mass and lower
impedance, a wider range of frequencies should be possible. The whistle is
still a single-note instrument, though.

What's the whistle principle? --direct a stream of fluid at an edge. Some
goes on each side of the edge. On one side, provide a chamber. The fluid
going to that side induces a pressure wave in the chamber, which returns as
a pressure pulse that pushes the fluid flow away from the chamber; more
travels on the "outside" of the edge than in. That induces a wave of low
pressure, which returns and pulls fluid flow to the chamber side, which
causes high pressure... you get the idea. Frequency is controlled by the
size/shape of the chamber and the speed of sound.

I'm dubious about reeds. They might work, but I personally have a hard time
with it.

Regards,
Ric
.

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