Klarinet Archive - Posting 000456.txt from 2004/10

From: Tony Pay <tony.p@-----.org>
Subj: Re: [kl] Re: Air flow
Date: Fri, 15 Oct 2004 18:59:43 -0400

On 15 Oct, Adam Michlin <amichlin@-----.com> wrote:

> At 03:15 PM 10/15/2004 -0700, Tim Roberts wrote:
>
> > It's the Bernoulli principle at work: moving air causes a reduction in
> > air pressure. When the air pressure behind the reed drops sufficiently,
> > it overcomes the strength of the reed and it begins to move, which
> > affects the column of air inside the clarinet, causing a feedback loop
> > that eventually increases the air pressure enough to the point where the
> > reed's inherent strength allows it to bounce back.
>
> Just so you all know, I have refunded Tim's price of admission for
> correcting my amateur physics.
>
> Now I just have to figure out how to explain the Bernoulli principle
> without thoroughly confusing everyone involved (including myself). Ah well.
> I'll get back to you all in a year or so with my revised document!

Though Bernoulli forces come into play as the reed gets really close to the
mouthpiece facing, and are why the design of the baffle inside the mouthpiece
tip is important, the simple difference in pressure between the inside of
mouth and the inside of the mouthpiece is the dominant force pushing the reed
against the facing.

See Benade, Fundamentals of Musical Acoustics, 437-439, 446-447.

Tony
--
_________ Tony Pay
|ony:-) 79 Southmoor Rd tony.p@-----.org
| |ay Oxford OX2 6RE http://classicalplus.gmn.com/artists
tel/fax 01865 553339

... He who laughs last, thinks slowest.

---------------------------------------------------------------------
Klarinet is a service of Woodwind.Org, Inc. http://www.woodwind.org