
Fundamentals of Acoustics and Structural Acoustics 29
© 2011 by Taylor and Francis Group, LLC
where
I
0
is the intensity of the incident wave (I
0
= P
0
2
/2ρ
0
c
0
, where P
0
is the pres-
sure in the incident wave, ρ
0
is the density of the medium, and c
0
is
the sound velocity in the medium)
ψ
s
(θ) is a distribution function
Several interesting cases can be noted. If ka ⇒ 0, then the wavelength of the
sound is very large compared with the radius of the cylinder, and the scat-
tered power goes to zero. This means that the sound travels as if the object
were not present at all. If the wavelength is very small compared with the
cylinder radius, it can be sho