Theoretical study on bubble dynamics of an underwater vacuum seismic source

This study presents a physical model of bubble pulsation for a vacuum seismic source designed for deep-sea resource exploration. A comprehensive review of the published literature reveals that systematic theoretical analyses of vacuum seismic sources remain extremely limited to date. The vacuum seismic source investigated in this paper is a novel seismic exploration technology. By exploiting the energy difference between the deep-sea ambient environment and the internal state of the vacuum source, a deep-sea cavity is generated, producing high-energy pressure waves suitable for deep-water exploration. In this work, bubble pulsation models for both the conventional air gun and the vacuum seismic source are established, and a comparative analysis is conducted to elucidate the fundamental differences between these two types of seismic sources. The operating mechanism of the vacuum seismic source is thereby revealed. Furthermore, the influences of initial cavity volume, initial pressure, and excitation depth on how the vacuum seismic source performs are systematically investigated. The results provide critical theoretical foundations for improving the quality of exploration pressure waves generated by vacuum seismic sources and for optimizing their spectral characteristics and offer essential theoretical support for the transition from a conceptual vacuum source model to the development of a prototype system.