涵道共轴双旋翼前飞气动特性与试验优选设计

Aerodynamic Characteristics and Test Optimum Design of Ducted Coaxial Rotors in Forward Flight

采用Fluent软件对涵道共轴双旋翼的前飞气动特性进行数值模拟研究,分别得出涵道双旋翼的升力、阻力和俯仰力矩随涵道前倾角、上下旋翼相对间距和来流速度的变化曲线.针对影响涵道共轴双旋翼升力的3个主要因素及其常用取值范围,采用正交试验法,以涵道前倾角α、上下旋翼间距H和来流速度v为试验因素,总升力FL为试验指标,设计25组试验,利用极差分析法对试验结果进行计算.结果表明:上述因素在取值范围内的变化对涵道共轴双旋翼总升力的影响程度的主次顺序为:上下旋翼间距,涵道前倾角,来流速度.最后,根据试验结果选定最优方案.

The aerodynamic characteristics of ducted coaxial rotors in forward flight were numerically simulated with Fluent. The curves indicating the lift, drag and pitching moment of ducted coaxial rotors with the change of the forward tilt angle, H/R and airflow velocity were obtained respectively. 25 groups of tests were designed by orthogonal test to study the three main factors that influence the lift, which include forward tilt angle a, different rotor distances H and airflow velocity v with total lift FL as the test index. The test results were calculated by range analysis, which show that the rank of influence degree on the total lift of ducted coaxial rotors with the above factors changing in common use range is： different rotor distances, forward tilt angle, airflow velocity. Finally, optimal scheme is selected according to the test results.