Computational Analysis of Autonomous Underwater Vehicles (AUVs) Structural Dynamics and Impact Forces During High Speed Water Entry

Understanding the structural response of Autonomous Underwater Vehicles (AUVs) during water entry is essential for ensuring operational safety and reliability. This paper introduces a bidirectional fluid-structure coupling numerical algorithm to analyze the structural response characteristics of an AUV during water entry at various speeds and angles. The numerical method’s accuracy is verified through experimental data. The investigation focuses on the water entry process within the velocity range of 50 to 200 m/s and entry angles between 60° and 90°. The study examines the influence of structural position, entry velocity, and entry angle on the structural response, while analyzing stress and strain at specific locations on the circular end face, cylindrical side, and circular tail surface of the AUV. The findings demonstrate that at entry speeds exceeding 100 m/s, the structure undergoes strain, with entry velocity exhibiting a more pronounced effect on axial force compared with entry angle. A reduced entry angle decreases the initial water contact duration and minimizes stress concentration. These results provide significant theoretical foundations for AUV structural design.