Re: [Phys-L] sound intensity problem

["Woolf, Lawrence" <Lawrence.Woolf@ga-asi.com>]

-----Original Message-----
From: Phys-l On Behalf Of John Denker
Sent: Friday, April 05, 2013 2:39 PM
The attenuation is hugely dependent on frequency, as you would expect based on kinetic theory, i.e. on the fact that air is made of atoms with a nonzero mean free path.  Viscosity and thermal conductivity will "short out" the peaks and troughs, especially if the peaks and troughs are relatively nearby.
The dependence on humidity is harder to figure, but still significant.

===================================

Some data on the effects of humidity are in the following reference:
<http://www.coe.montana.edu/ee/rmaher/publications/maher_aac_0704.pdf>
Figure 4

And the following is an interesting article about sound refraction:
http://www.flyoakland.com/pdf/refraction_sound_atmosphere.pdf

Larry Woolf