In the field of oscillating hydrofoil research, the choice of hydrofoils is still mainly based on traditional NACA airfoils. The article explores the hydrodynamic characteristics of other airfoil structures to further improve the applicable range of hydrofoil working environments. By applying the swept structure of fish tail fins through biomimetic methods to oscillating hydrofoils, a motion model of the swept oscillating hydrofoil is established, and the relevant mathematical expressions and parameter definitions are described. Through numerical simulation methods, the effects of the pitch axis position and the tip-to-root ratio on the performance of the swept oscillating hydrofoil are analyzed. The simulation results show that the pitch axis position has a significant impact on the various force characteristics and energy acquisition efficiency of the hydrofoil, while the tip-to-root ratio mainly reflects the degree of sweep of the hydrofoil, thereby affecting the lift-to-drag ratio and the moment coefficient of the swept hydrofoil. Selecting the appropriate pitch axis position and tip-to-root ratio will enhance the lift of the hydrofoil while reducing the drag experienced.

Abstract
1. Introduction
2. Establishment of the Motion Model
    2.1 Two-Dimensional hydrofoil Motion Model
    2.2 Motion Model of Trailing-Edge Oscillating Hydrofoil
    2.3 Calculation of Energy Efficiency for Trailing-EdgeOscillating Hydrofoils
3. Numerical simulation method and gridindependenceverification
    3.1 Verification of Simulation Methods
    3.2 Grid Independence Verification
4. Research Results and Analysis
    4.1 Influence of Pitch Axis Position on the HydrodynamicPerformance of Aft-Swept Hydrofoils
    4.2 Influence of Aspect Ratio on the HydrodynamicPerformance of Aft-Swept Hydrofoils
5. Conclusion
References

• CHEN Zhuo(School of Naval Architecture and Port Engineering, Shandong Jiaotong University, China)
• SUN Guang(School of Naval Navigation and shipping, Shandong Jiaotong University,China)
• JIAO Bo(School of Naval Architecture and Port Engineering, Shandong Jiaotong University, China) Corresponding author