Sound Scattering and Its Reduction by a Janus Sphere Type
Figure 4
The frequency variation of the vertical location of the boundary between the hard and soft zones of the sphere. Zero location means the boundary is at the sphere’s centre. The location of the boundary was optimised to minimise the scattered acoustic power and is plotted for when the sphere is (a) in free space, (b) its centre is 2.1 m away from a free surface, and (c) 2.1 m away from a hard ground. The rest of the conditions are as in Figure 3.
