The acoustic emission from a nonlinearly oscillating charged drop

A charged drop oscillating in a compressible medium is capable of emitting acoustic waves. According to calculations in the constant drop volume approximation linear in the oscillation amplitude, the most intense acoustic emission corresponds to the dominant mode. An acoustic dipole emission related to the excitation of a translational mode is only revealed by calculations in the second order of smallness with respect to the oscillation amplitude, in the case when two adjacent modes are present in the spectrum of initial deformations.