仿鸟扑翼机器人气动力建模与分析

Aerodynamic Modeling and Analysis of Biomimetic Flapping-Wing Robot

采用改进的叶素理论对仿鸟扑翼机器人的空气动力学问题进行了研究,建立了低雷诺数、非定常条件下,仿中小尺度飞鸟扑翼机器人的扑动模型和扭转模型,并考虑非定常尾涡对展向气流的下洗效应,对飞行迎角进行了修正.在此基础上,建立了扑翼机器人的升力模型和推力模型.实验数据与仿真结果基本吻合,较好地揭示了气动力在下扑和上扑阶段的变化趋势.以该模型为基础,进一步分析了扑翼机器人的飞行机理和气动特性,发现升力由扑翼内、外翼段共同产生,而推力主要由外翼段产生,且改变扑翼频率对推力的影响要大于升力.结果表明,文中方法在仿鸟扑翼机器人的气动力分析方面是有效的.

In this paper,the aerodynamic performances of a biomimetic flapping-wing robot is investigated based on the modified blade element theory,and the flap and the twist models for a robot in meso-and-micro scale are established in the conditions of low Reynolds numbers and unsteady aerodynamic behaviors.Then,the attack angle is modified according to the downwash effect caused by unsteady wake flow,based on which the numerical models of the lift force and the thrust force are presented.The experimental results basically accord with the simulated ones,showing a similar tendency of aerodynamic forces during the downstroke and upstroke of the robot.Finally,based on the proposed models,the flying mechanism and aerodynamic characteristics of the flapping-wing robot are further analyzed.It is found that the lift force is generated by both the inner and the outer wings,while the thrust force is mainly by the outer wing;and that,as compared with the lift force,the thrust force is more sensitive to the flap frequency.It is thus concluded that the proposed method is effective in the aerodynamic analysis of biomimetic flapping-wing robots.