Liao Yuankun, Cheng Kai, Sun Wuhe, Zhao Yan, Jia Xiaojie, Qi Wanrong
School of Mechanical and Aerospace Engineering, Jilin University, Changchun, 130022, China.
Light Alloy Research Institute, Central South University, Changsha, 410000, China.
Heliyon. 2024 Oct 2;10(19):e38804. doi: 10.1016/j.heliyon.2024.e38804. eCollection 2024 Oct 15.
Long-endurance unmanned aerial vehicles (UAVs) play an increasingly important role in various aspects of societal life. In response to the national emphasis on air force development, a study on the aerodynamic characteristics of long-endurance UAVs was conducted. This paper utilizes SolidWorks software to construct a geometric model based on the MQ-9 UAV, and a CFD method to establish a simulation model for UAV cruising flight. The aerodynamic coefficients, required thrust, and total mass during UAV cruise were calculated, and the variation of aerodynamic coefficients as airflow passes through the UAV was described. A comparative analysis was performed on the effects of different angles of attack, flight speeds, and flight altitudes on aerodynamic efficiency. The study results indicate that at an altitude of 10 km, with a 0° angle of attack, the UAV achieves a lift coefficient of 0.8888, a drag coefficient of 0.0679, and a lift-to-drag ratio of 13.0988. The required thrust is approximately 2236 N, and the total flight mass is approximately 3090 Kg. The angle of attack has the greatest impact on aerodynamic efficiency, followed by flight altitude, while flight speed has the least impact on aerodynamic performance. The lift-to-drag ratio initially increases sharply and then decreases rapidly with increasing angle of attack. It is recommended to control the angle of attack within the range of 0°-6°. The lift-to-drag ratio increases slowly with increasing flight speed, suggesting that the flight speed should be maintained near the maximum cruise speed. The lift-to-drag ratio generally decreases with increasing flight altitude, and it is recommended to maintain the flight altitude within the range of 9 km-11 km.
长航时无人机在社会生活的各个方面发挥着越来越重要的作用。为响应国家对空军发展的重视，开展了一项关于长航时无人机空气动力学特性的研究。本文利用SolidWorks软件基于MQ-9无人机构建几何模型，并采用CFD方法建立无人机巡航飞行的仿真模型。计算了无人机巡航时的空气动力学系数、所需推力和总质量，并描述了气流通过无人机时空气动力学系数的变化。对不同攻角、飞行速度和飞行高度对空气动力学效率的影响进行了对比分析。研究结果表明，在10千米高度、攻角为0°时，无人机的升力系数为0.8888，阻力系数为0.0679，升阻比为13.0988。所需推力约为2236牛，总飞行质量约为3090千克。攻角对空气动力学效率影响最大，其次是飞行高度，而飞行速度对空气动力学性能影响最小。升阻比随攻角增大先急剧增大后迅速减小。建议将攻角控制在0°-6°范围内。升阻比随飞行速度增加而缓慢增大，表明应将飞行速度保持在最大巡航速度附近。升阻比一般随飞行高度增加而减小，建议将飞行高度保持在9千米-11千米范围内。
