飞机模型俯仰-滚摆耦合复杂流场测试系统设计

为真实地模拟飞机机动飞行和分析俯仰－滚摆耦合状况下的动态气动特性和复杂流动机理，首次在风洞中实现了模拟飞机的俯仰与滚转的复合运动。使用E型架结构实现飞机模型俯仰角α的正弦运动，同时在E型架上安装交流伺服电机直接控制飞机模型的滚转角Φ；本系统采用了旋转编码器的输出脉冲来测量模型的转角，并记录下该脉冲出现的时刻，用这些数据得到飞机模型在风洞实验中滚转角的时间历程和滚转力矩特性，并用激光片光系统进行流态显示，使用这套系统得到了俯仰－滚摆耦合运动下的气动特性。分析表明，俯仰－滚摆耦合状况下进一步推迟了滚摆开始攻角，不稳定性增加，同时证明该系统满足风洞实验要求。

Measuring system design for unsteady flow field of aeroplane model about a coupled pitching- rolling movement

In order to imitate maneuvering flight of the aeroplane and analyze the aerodynamic character in dynamics and complex flow principle in the condition of coupled pitching and rolling oscillation, it was realized for the first time that the coupled motion of pitching and rolling was imitated in the wind tunnel experiment. The sine motion of pitching angle a of airplane model was realized by using E - type frame, and rolling angle (p of aeroplane model can be controlled directly by AC servo motor fixed on the E frame. The models roll angle was measured by the output - pulse of rotary encoder, and the simultaneous time which the pulse appeared was recorded in the system. So the time history of roll angle of plane model in the wind tunnel experiment could be calculated with those data. Moreover, the flow visualization was showed by the laser system. The aerodynamic character was obtained by using the system. It showed that the attack angle at which rolling oscillation started shifted to higher angle in the coupled pitching and rolling oscillation motion and the unsteadiness increased. In the meanwhile, it showed that the system could meet the requirements of the wind tunnel experiment.