Vol. 11, No.1, pp.60-63 (2017)
【ここにタイトル】
L. Zhang, X. Zhu, Y. Huang, Z. Liu, and K. Yan
Department of Chemical and Biological Engineering, Zhejiang University, China
Abstract
Acoustic signals can be generated with a corresponding bubble oscillation induced by spark discharge. Plasma sparker has been applied in the oceanic seismic exploration for decades. In order to get high resolution seismic exploration at great water depth, the so-called deep-towed plasma sparker was proposed. In this paper, the acoustic characteristics under the water pressure ranging from 0.1 to 1.0 MPa are demonstrated. The experimental results indicate that the expansion pulse peak has nothing to do with the water pressure ranging from 0.1 to 1.0 MPa. However, the collapse pulse peak changes violently with the increasing of the ambient pressure. The collapse pulse peak falls by half approximately from 0.1 MPa to 1.0 MPa, and is not stable comparing to the expansion pulse peak. In addition, the acoustic energy and electro-acoustic energy efficiency decrease when the ambient pressure increases. The fundamental frequency increases dramatically from 500 to several thousand Hertz with the increasing of ambient pressure.
Keywords - Spark discharge, ambient pressure, acoustic characteristic