Movement simulation and experimental analysis of a deep-sea acoustic submerged buoy based on an acoustic vertical array

• A deep-sea near-bottom acoustic submerged buoy integrated with a large-aperture vertical array is designed, realizing the integration of multiple functional systems. • Hydrodynamic models based on CFD simulation software are established to accurately simulate the sinking and floating processes of the submerged buoy, with simulation results highly consistent with sea trial data. • The vertical array maintains a nearly vertical posture (inclination angle ±1°) during long-term mooring, and adjacent array segments have a stable depth difference of 60m. • High-consistency ocean ambient noise data are obtained, revealing the composition of deep-sea noise (distant ship noise + wind-related noise) and providing a basis for target positioning. • The submerged buoy achieves safe and controllable deployment/retrieval in 4068m deep sea, with horizontal displacement within 324.3m, verifying the engineering feasibility of the scheme. Based on a large-aperture acoustic linear array, an acoustic submerged buoy equipped with a vertical array was constructed near the bottom of the deep sea. The hydrodynamic model was established to simulate the process of sinking and floating, which were basically consistent with the experimental result. The depth difference between adjacent depth sensors was about 60m, which is corresponding to the length of each section of the linear array. Meanwhile, the inclination angles of each section fluctuated within ±1°, which indicated that the linear array was in a nearly vertical posture. The acoustic sensors’ data showed that the received ocean ambient noise levels of each array element were highly consistent. It was about 52dB at 1000Hz, reaching the background noise level of the ocean under sea state 1. The noise was composed of distant ship noise with a peak at around 50Hz and wind noise with a slope of -5dB/octave. The ship noise level of the low-frequency band was independent of the sea state. The beamforming results preliminarily verified the feasibility of target sound source localization. The acoustic submerged buoy successfully achieved the goal of vertical deployment, retrieval and long-term operation of a large-aperture acoustic linear array near the bottom of the deep sea, and obtained a batch of high-quality acoustic propagating and ambient noise data. It provides guidance for the optimization design and engineering test of the deep-sea acoustic submerged buoy.