Ultra low frequency electromagnetic underwater sound source

Abstract

A detail analysis is presented of one ultra low frequency sound source which is smaller and lighter than conventional piezoelectric ultra low frequency sound source. This sound source is single piston vibration using the electromagnetic principle. The radiation characteristic of sound source is researched by single piston radiation model in low frequency. The dynamic characteristic such as resonant frequency, vibrant displacement of sound source is researched by analytic method and finite element method. In analytic method, the electricity-magnetism, magnetism-force, and force-vibration conversion models of sound source are established by differential equations in different coupling physical fields, and the dynamic characteristics based on the conversion models are simulated by combining and solving differential equations using the Matlab/Simulink. In finite element method, using transient solver of electromagnetic analysis finite element software Ansoft, the dynamic characteristics of sound source are solved. Optimizing the dynamic characteristic of sound source by adjusting magnetic circuit, drive coil, and elastic component parameters, the resonant frequency and radiated sound power of sound source are determined. One prototype sound source design, in which the source level is 184 dB in frequency 73 Hz by calibration, is fabricated that demonstrated proof-of-concept.