S. Taherzadeh et al., SOME PRACTICAL CONSIDERATIONS FOR PREDICTING OUTDOOR SOUND-PROPAGATION IN THE PRESENCE OF WIND AND TEMPERATURE-GRADIENTS, Applied Acoustics, 54(1), 1998, pp. 27-44
The propagation of low-frequency sound above an impedance plane in a v
ertically stratified medium is considered. The combined effects due to
the vector wind and temperature gradients on sound propagation are st
udied. Recently, a WKB-type approximation has been combined with turni
ng point theory and applied to the efficient computation of the height
-dependent Green's function, which, in turn, has been used in the fast
field program (FFP). Although this method is applied to a temperature
-stratified medium, it leads to a significant reduction in the computa
tional time for predicting sound propagation outdoors. The present pap
er extends such a WKB-type approximation to include vector wind. Atten
tion is focused on the development of efficient algorithms for numeric
al evaluation of the inverse Fourier transform and on considerations o
f numerical stability. The limitations of the approximation are examin
ed for logarithmic profiles in particular. (C) 1997 Elsevier Science L
td.