Efficiency of parametric ultrasound generation in relaxing media for very shallow-water echo sounders

Autor: Ordoñez-Cebrian, Patricia, Jimenez, Noe, Espinosa Roselló, Víctor, Puig Pons, Vicente, Soliveres, Ester
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Zdroj: RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
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Popis: Parametric acoustic generation provides the possibility to obtain narrow and nearly side-lobe free acoustic beams for low frequencies. In this way, the nonlinear interaction of two intense beams with close frequencies generates combinations of the spectral components: high frequency harmonics, difference-frequency harmonics and sum harmonics. The most used in underwater acoustics to obtain the advantages above mentioned is the difference-frequency harmonic for its lower attenuation. Moreover, sea water ultrasound absorption presents not only thermo viscous, but also ionic relaxation losses, both at the primary beam (due to magnesium sulfate presence), and at lower frequencies (boric acid ions). In this work, a computational finite differences method for nonlinear acoustical propagation with relaxation losses is employed to study the efficiency of the parametric sound generation in sea water. Thereby, we present the design and development of parametric echo sounders for very shallow water (
The work was supported by Spanish Ministry of Science and Innovation through project FIS2011-29731-C02-01.
Databáze: OpenAIRE