Song Wenda, Mu Zhengzhi, Wang Yufei, Zhang Zhiyan, Zhang Shuang, Wang Ze, Li Bo, Zhang Junqiu, Niu Shichao, Han Zhiwu, Ren Luquan
Key Laboratory of Bionic Engineering of Ministry of Education, Jilin University, Changchun 130022, China.
School of Mechanical and Aerospace Engineering, Jilin University, Changchun 130022, China.
Polymers (Basel). 2022 Jun 23;14(13):2552. doi: 10.3390/polym14132552.
Rotor plays a vital role in the dynamical system of an unmanned aerial vehicle (UAV). Prominent aerodynamic and acoustic performance are a long-term pursuit for the rotor. Inspired by excellent quiet flight characteristics of owls, this work adopted bionic edge design and rational material selection strategy to improve aerodynamic and acoustic performance of the rotor. A reference model of rotor prototype with streamlined edges was firstly generated by reverse engineering method. With inspiration from owl wings and feathers, bionic rotors with rational design on leading and trailing edges were obtained. Original and bionic rotors were fabricated with polyamide PA 12 and Resin 9400 by 3D printing technique. Aerodynamic and acoustic performance of the as-fabricated rotors were experimentally measured and analyzed in detail using a self-established test system. Comparative experimental results indicated that the aerodynamic and acoustic performance of the rotors was closely related to the bionic structures, material properties, and rotational speeds. At the same rotational speed, bionic rotor fabricated with Resin 9400 can produce a higher thrust than the prototype one and its power consumption was also reduced. The resulting noise of different bionic rotors and their directivities were comparatively investigated. The results verified the bionic edge design strategy can effectively control the turbulent flow field and smoothly decompose the airflow near the tailing edge, which resulting in enhancing the thrust and reducing the noise. This work could provide beneficial inspiration and strong clues for mechanical engineers and material scientists to design new abnormal rotors with promising aerodynamic and acoustic performance.
旋翼在无人机动力系统中起着至关重要的作用。卓越的空气动力学和声学性能是旋翼长期以来的追求目标。受猫头鹰出色的安静飞行特性启发，本研究采用仿生边缘设计和合理的材料选择策略来提升旋翼的空气动力学和声学性能。首先通过逆向工程方法生成了具有流线型边缘的旋翼原型参考模型。借鉴猫头鹰翅膀和羽毛的特点，获得了在前缘和后缘设计合理的仿生旋翼。采用聚酰胺PA 12和树脂9400通过3D打印技术制造了原始旋翼和仿生旋翼。利用自行搭建的测试系统对制造好的旋翼的空气动力学和声学性能进行了详细的实验测量和分析。对比实验结果表明，旋翼的空气动力学和声学性能与仿生结构、材料特性和转速密切相关。在相同转速下，用树脂9400制造的仿生旋翼比原型旋翼能产生更高的推力，且功耗也有所降低。对不同仿生旋翼产生的噪声及其指向性进行了对比研究。结果验证了仿生边缘设计策略能够有效控制湍流场，并使尾缘附近的气流平稳分解，从而提高推力并降低噪声。这项工作可为机械工程师和材料科学家设计具有良好空气动力学和声学性能的新型异形旋翼提供有益的启发和有力的线索。
