sound waves in wind (doppler like shift?)

Mook Johnson · science forum beginner Joined: 21 Jul 2006 Posts: 1

We all know the classic doppler effect of when there is relative motion
between the acoustic source and a observer.

If an observer is standing upwind of an acoustic source would there be a
small but measureable change in the pitch of the sound due the the fact that
the medium that the sound wave is moving through is also moving?

I'm visualizing a fixed observer and speaker in a wind tunnel.

The speaker is a piston creating say 1KHz continuous tone(1 compression wave
per mS). The air speed is 0.5 the speed of sound (ignore winds noises). When
the comression wave is made by the speaker, it moves through the air, upwind
and downwind, at the speed of sound. since the mass of air is moving
relative to the observer upwind, the the compression wave will only extend
towards the observer 1/2 the distance it normally wound in still air before
the next compression wave is created by the speaker.

This continues to happen until the wave finally reaches and the comression
waves are spaced more closely together which is an increase in pitch.

The opposite happens downwind of the speaker.

Is my thinking valid?

N:dlzc D:aol T:com (dlzc) · science forum Guru Joined: 25 Mar 2005 Posts: 2835

Dear Mook Johnson:

"Mook Johnson" <mook@mook.net> wrote in message
news:283wg.3471$YO6.1911@tornado.texas.rr.com...

Gordon · science forum Guru Wannabe Joined: 12 May 2005 Posts: 115

On Fri, 21 Jul 2006 11:46:06 GMT, "Mook Johnson" <mook@mook.net>
wrote:

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