Research on Damage and Cavitation Characteristics of Propellers under Far Field Shock Waves

Propellers serve as pivotal components within ship propulsion systems, directly influencing a vessel's performance through their stability and efficiency. Current research on the resilience of propulsion shafts often simplifies propellers to homogenous discs, neglecting their structural intricacies. This approach fails to accurately capture the transient damage features of propellers under the effects of underwater explosion. Therefore, this paper takes into consideration the propeller's structural characteristics. By initially employing wet modal analysis, the study determines that solid modeling outperforms shell modeling. It investigates the response and damage characteristics of propeller surfaces under the influence of far-field shockwaves while considering the propeller's structural attributes. The paper also analyzes the transient damage characteristics of propellers in conjunction with the hydrodynamic cavitation state generated during high-speed propeller rotation. The research findings demonstrate that at attack angles of 0 degrees and 90 degrees, surface loads on the propeller due to shockwave incidence are higher, but they exhibit an upper limit that correlates with the propeller's structural features. When accounting for the hydrodynamic cavitation state, stress levels on the blades remain consistently uniform. The primary plastic damage zone on the blades is near the root, showcasing both local and complete plastic deformation modes. This paper delves into the damage and cavitation characteristics of propellers under far-field explosions, and its results offer valuable insights for protecting propulsion shafts and propellers against shock impacts.