波浪驱动柔性胸鳍摆动推进机理研究

Based on the wave glider and biomimetic manta ray robot fish, one new batoid-inspired wave glider using flexible pectoral fin oscillation propulsion is proposed to avoid the convective turbulence between hydrofoils, which is caused by the original rotating joint hydrofoil propulsion. This bionic propulsion improves the efficiency of conversion from wave energy to kinetic energy, such that it better meets the needs of long time unmanned exploration in the deep sea. Preliminary tests demonstrate that the flexible fin is able to oscillate during the up-and-down process and produce the thrust. To deeply investigate its propulsion mechanism, the research contents of this project includes: 1) build the multi-body kinetic model of the batoid-inspired rigid wave glider under wave actions, and perform wave tank experiments to correct the up-and-down velocity solution; 2) perform the still water up-and-down experiments based on the velocity solution, observe the trajectory, flow structure and horizontal thrust of the pectoral fin under the action of potential energy, and build the kinematics equations of the flexible pectoral fin oscillation locomotion; 3) convert the equations of motion into moving boundary conditions, build the moving mesh based flexible pectoral fin oscillation simulation method, which is able to accurately predict the thrust fluctuation and vortex shedding period, reveal the rule and cause of the thrust, and build the thickness distribution, size and hardness dependent kinematic model and wave energy conversion efficiency model. The execution of the project will provide the theoretical basis for the realization of the wave driven flexible pectoral fin oscillation propulsion, and novel ideas for the application of bionic propulsion in surface vehicle.

在波浪滑翔器与仿蝠鲼机器鱼的基础上，提出一种仿蝠鲼波浪滑翔器，采用柔性胸鳍摆动推进方式，避免原有转动关节水翼之间的对流扰动，提高波浪能转化为动能的效率，以适应深海长时间无人探测需求。预实验显示柔性胸鳍随波浪升降时会自然摆动并产生推力，为深入研究其推进机理，本项目开展下述研究：1）建立波浪作用下仿蝠鲼波浪滑翔器多刚体结构升降运动的动力学模型，并开展波浪水池试验修正速度解；2）基于速度解开展静水升降试验，观测柔性胸鳍在势能作用下的运动轨迹、流场结构与水平推力，建立柔性胸鳍摆动的运动学方程；3）将运动学方程转化为动边界条件，建立基于动网格的柔性胸鳍摆动数值模拟方法，可准确预测推力波动与涡脱落周期，揭示推力产生的规律与原因，进一步建立依赖于胸鳍厚度分布、尺寸和硬度的运动学方程和波浪能转化效率分析模型。项目实施为波浪驱动柔性胸鳍摆动推进方式的实现建立理论基础，为仿生推进应用于水面航行器提供新的思路。

本项目在波浪滑翔器与仿蝠鲼机器鱼的基础上，提出一种仿蝠鲼波浪滑翔器，采用柔性胸鳍摆动推进方式，避免传统转动关节水翼之间的对流扰动，提高波浪能转化为动能的效率，以适应深海长时间无人探测需求。为深入研究柔性胸鳍随波浪升降时自然摆动并产生推力的机理，本项目开展了下述研究：1）建立波浪作用下仿蝠鲼波浪滑翔器多刚体结构升降运动的动力学模型，利用三维重构技术建立仿蝠鲼波浪滑翔器的缩比模型，并采用3D打印技术配合硅胶灌模制作物理模型，并开展波浪水池试验；2）设计静水升降实验平台，利用步进电机控制模型以特定速度升降，应用PIV设备测量不同硬度仿蝠鲼波浪滑翔器模型在升降过程中某二维平面的流场结构，为数值模拟提供验证数据；3）建立基于动网格的柔性胸鳍摆动数值模拟方法，通过双向流固耦合，预测推力波动与涡脱落周期，揭示推力产生的规律与原因。项目实施为波浪驱动柔性胸鳍摆动推进的实现建立理论基础，为仿生推进应用于水面航行器提供了理论支持和技术储备。