A STUDY OF THE SCATTERING OF SOUND WAVES IN FLUIDS. PART I. SCATTERING OF A PLANE WAVE BY A SPHERICAL BUBBLE

Abstract

Abstract : An analysis was made of the scattering of a plane wave by a spherical bubble immersed in a homogeneous, perfect fluid of infinite extent. An expression was obtained for the average sound intensity of the scattered wave in close proximity to the bubble. The case of long wave lengths or small bubble radii was given special consideration. Numerical results are presented in polar- diagram form for several values of R/a and 2-pi-a/lambda, where r is the distance from the bubble center, a is the bubble radius, and lambda is the wave length. An expression for the average total intensity of the entire sound field was compared with the average sound intensity of a plane were traveling in an infinite homogeneous fluid with no bubble present. The influence of the bubble on the average total sound intensity is negligible for small values of 2 pi-a/lambda and r/a > > 10. For small values of r/a, the presence of a bubble considerably alters the magnitude of the average total sound intensity from that of a plane wave. Polar diagrams of the ratio of the average total sound intensity to the average intensity of the incident plane wave are presented for several values of r/a.