长航时轻型固定翼农用遥感无人机设计与仿真

针对电动无人机应用于农业遥感监测时受其续航时间限制的问题,从实际应用角度出发,设计了一种续航时间长、适用于农业遥感监测的翼身融合布局的轻型电动固定翼无人机。提出了翼身融合布局轻型固定翼无人机的总体设计方法,确定了轻型固定翼无人机的结构参数,建立了物理模型并对其参数进行了优化分析。通过计算流体力学(Computational fluid dynamics,CFD)分析计算了翼身融合布局轻型固定翼无人机的气动性能,基于流固耦合模型动态分析了其飞行状态下的受力分布。结果表明,优化模型较初始设计模型的升阻比提高了2.6%,在迎角为6°、巡航速度为15.5 m/s时,所设计的翼身融合布局轻型固定翼无人机机身压力分布合理,且拥有良好的气动特性。起飞质量为1.5 kg时,无人机下表面压力最大,为143 Pa,升力主要集中在机翼前缘部分,计算所得理论续航时间为65 min,在巡航阶段最大变形量0.288 38 mm,符合飞行器工作条件,无人机结构和选用材料均满足设计和使用要求。本文设计的电动轻型固定翼农用遥感无人机在结构、材料和性能方面均适用于农业遥感监测。

Design and Simulation of Long-endurance and Light Agricultural Remote Sensing Fixed-wing UAV

The application of electric unmanned aerial vehicles (UAVs) in agricultural remote sensing monitoring is limited by their short endurance. A long-endurance battery-powered light blended-wing-body UAV was designed for agricultural remote sensing. A design method for a light blended-wing-body UAV was proposed. The structural parameters of the light fixed-wing UAV was optimized and a model was built. The aero-dynamic performance of the UAV was determined by computational fluid dynamics (CFD), and the force distribution in flight state was dynamically analyzed based on fluid-structure interaction model. The results showed that the lift-to-drag ratio of the optimized model was 2.6% higher than that of the initially designed model, and the light blended-wing-body UAV had good aerodynamic characteristics. The pressure distribution of the UAV was effective at a 6° angle of attack and a cruising speed of 15.5m/s. When the take-off weight was 1.5kg, the maximum value of pressure on the lower surface of the UAV was 143Pa, and the lift force was mainly concentrated on the leading edge of the wing. The theoretical endurance time was 65min, and the maximum stress during the cruising phase was lower than the tensile strength of the fuselage material and the yield strength of the rotor. Under the same conditions, the maximum value of total deformation was 0.28838mm. The above parameters all met the normal working conditions of the UAV. Therefore, the structure, materials, and performance of the proposed light agricultural remote sensing UAV were suitable for agricultural remote sensing. It also provided a design method and key technologies for the application of electric drones.