Applications of the combustive sound source

Abstract

The combustive sound source (CSS) can be used to generate high-intensity, low-frequency acoustic energy in a variety of mediums by using deployment configurations suitable to each medium. The basic principle of operation remains configuration independent. A gaseous fuel/oxidizer mixture is introduced into a combustion chamber and ignited with a spark. The ensuing combustion produces a bubble of expanding gas which, in turn produces high-intensity, low-frequency acoustic pulses. Three different deployment configuration experiments will be discussed, including water column, ocean-bottom seismic, and earth-surface seismic. In-situ measured energy levels and spectra produced by CSS are compared to other sources typical to each medium, including explosive and inertial. It is shown that CSS is capable of producing bulk waves in both water and earth mediums, as well as seismic interface waves for both air/earth and water/sea floor cases. It is demonstrated that CSS is a truly versatile acoustic energy source with a low cost deployment configuration which can be tailored easily to different environments. [Work supported by the U.S. Navy Office of Naval Research.]

An investigation of the combustive sound source

“…Measured energy levels and spectra from a CSS were compared to that of similar sources used for each medium. These tests confirm the versatility and cost efficiency of deployment for each configuration [16].…”

An investigation of the combustive sound source.

“…A relation between bubble pressure, volume, and potential energy was found by Willis [21] in 1941, 16) where Q is the potential energy of the bubble. A relationship between T and Q can be obtained by solving Eqs.…”

“…Previous versions of the CSS failed to meet these needs. Analysis of the previous work [11,12,16] insight into improvements that were made, which allowed the CSS to more closely meet the desired goals.…”

“…Furthermore, past misuse of underwater explosive charges has led to the death of at least two individuals [18]. This led to the temporary ban of underwater explosive charges and initiated CSS research [11,12,16]. Recent improvements to the CSS provide inherent safety features as well as a minimal duty cycle to reduce the hazardous nature of the device.…”