Nd and 1, may be facilitated by using the special properties of the induction near-sound field 
of dipoles and quadrupoles. 
SUMMARY 
In summary, the near-field properties of the general sound field of dipoles, lateral quad- 
rupoles, and longitudinal quadrupoles, as well as isotropic turbulence, have been discussed 
for various assumed conditions. The general expressions for the rms sound pressure are ex- 
pected tobe the most useful in practical applications. These applications would include the 
analysis of internal noise and structural loads caused by jets, propellers, and the boundary 
layer of aircraft and ships; the analysis of surface and turbulence noise in the close vicinity 
of wind tunnels and water tunnels; and the analysis of surface and turbulence noise in the 
vicinity of the boundary layer of objects moving in air or water. To facilitate the use of the 
equations inthese applications, a number of useful concepts are also given. 
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