Abstract: Motivated by the profound impacts of longitudinal and transverse waves of earthquake, a novel underwater bionic propeller that utilized longitudinal and transverse compound wave patterns was proposed and designed. A kinematic model incorporating the composite waves was theoretically established, alongside the development of a physical prototype and testing platform. The propulsion performances of the propeller were systematically compared and analyzed through CFD simulations as well as prototype tests under varying amplitudes of longitudinal wave superposition. Simulation results show that both the thrust and velocity generated by the undulating fin may be significantly enhanced, with mean thrust increasing by 27.6% and peak thrust exceeding 200%. Experimental results reveal that under a frequency of 2 Hz with a longitudinal-wave amplitude of 20°, the steady-state average velocity achieved by the propeller reaches 0.761 m/s, which is approximately 14.7% greater than that of without longitudinal wave. This paper demonstrates that composite wave bionic fins exhibit superior thrust and velocity performance compared to single sinusoidal wave configurations, thereby offering an innovative propulsion mechanism for advancing high-performance bionic fish robots.

Key words: compound wave, underwater propeller, undulating fin, bionic fish robot

摘要： 受地震纵波和横波复合作用具有极大破坏性的启发，提出并设计了一种纵横复合波动新型水下仿生推进器。理论上建立了纵横复合波动运动学模型，开发了物理样机与测试平台，通过计算流体动力学(CFD)仿真和物理试验对比分析推进器在不同纵波幅值叠加下的推进性能。仿真结果表明，纵横复合波动能够显著增大波动鳍的推力和速度，推力均值可提高27.6%，峰值增大幅度大于200%。试验结果表明，推进器在2 Hz频率和20°纵波幅值下的稳态平均速度达到0.761 m/s，相比无纵波时提高约14.7%。该研究结果表明，相较于单一正弦横波，复合波动仿生鱼鳍具有更好的推力和速度性能，为高性能仿生波动机器鱼的研制提供了一种新的推进机理。

关键词: 复合波动, 水下推进器, 波动鳍, 仿生机器鱼