Back to Kemp Acoustics Home
Next: Multimodal equations at a
Up: Solutions for a uniform
Previous: Loss-less propagation
  Contents
Lossy propagation may be represented as with
circular cross-section by working
out the lossy
direction wavenumber, (Bruneau et al [44]).
Starting from the lossy boundary condition gives
as
 |
(2.70) |
where
is the square of the non-lossy version of
which in
rectangular geometry is
 |
(2.71) |
The real part of the correction to
is [44]
 |
(2.72) |
where the boundary specific admittances are
 |
(2.73) |
 |
(2.74) |
with
and
.
The imaginary part of the correction to
is [44]
 |
(2.75) |
Using the same method as for cylindrical geometry,
is the sum of real
and imaginary parts
 |
(2.76) |
where
and
are given by
 |
(2.77) |
and
 |
(2.78) |
Back to Kemp Acoustics Home
Next: Multimodal equations at a
Up: Solutions for a uniform
Previous: Loss-less propagation
  Contents
Jonathan Kemp
2003-03-24