90° 
ae rah + (3cos*e -4cos*6 +1) 
a —--4(9cos*e -6cos*6 +1) 180° 
2 
aul 
for 22 => 
Figure 3 — Directional Patterns of Three Components of Mean-Square 
Sound Pressure in All Planes Containing the Axis 
of a Longitudinal Quadrupole 
\z 
Near Field T ep 
‘or Fie 
+ costo 
£ = (I-3cos@e)+ 8 $(-2sinecose) 
90° 
go° 270° 
180° 
180° 
Figure 4b 
Figure 4a 
Figure 4 — The Induction Near- and Far-Field Components of the Intensity 
Field in All Planes Containing the Axis of a Longitudinal Quadrupole 
Arrows indicate magnitude and direction. 
13 
