Abstract:
The combustive sound source (CSS) utilizes the combustion of a gaseous fuel-oxygen mixture to produce very low-frequency signals. Various different deployment configurations previously reported adapt CSS for use in the water column, on the ocean bottom, and on the earth's surface [Wilson et al., IEEE J. Ocean. Eng. 20, 311--320 (1995)]. There has been recent work in the development of a linear horizontal array consisting of up to four 2.5-liter elements. Measured acoustic signatures and spectra in the 10- to 1000-Hz band, which are produced by the combustion of methane and oxygen mixtures, are reported for individual elements and 2-, 3-, and 4-element arrays. Comparisons are made with the array performance of similar sources such as the air gun and sparker, as well as to model predictions. Finally, a prototype towed version of the single element CSS has been developed using an on-board electrolytic gas generator that enables the combustion of hydrogen. Signatures and spectra produced by the towed CSS will be compared to stationary CSS data and to other similar towed sources. [Work supported by the U.S. Navy Office of Naval Research.]