Klarinet Archive - Posting 000677.txt from 2003/08

From: ormondtoby@-----.net (Ormondtoby Montoya)
Subj: Re: [kl] closing the reed
Date: Tue, 26 Aug 2003 13:17:31 -0400

> It's driven by the Bernoulli Effect which when
> air is blown across, the air pressure lowers
> thus pulling the reed closed. The reed
> strength pulls the reed back away from the
> Mouthpiece and completes the vibration.

Just for the record, according to Benade (Fundamentals of Musical
Acoustics, pg. 438), the Bernoulli effect is part of the story, but only
a small part. He explains that the Bernoulli force varies during the
cycle (rate of air flow varies during the cycle), but experimental
results were:

"...in the simplest case, the Bernoulli force is about 3.5% of the
maximum total force acting on the reed due to pressures P and p"

where P = the musician's blowing pressure, and p = the fluctuating
pressure inside the mouthpiece.

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