非定常自由来流对飞机模型气动特性的影响

在国内首座非定常风洞中，研究了不同幅值、不同频率脉动的非定常自由来流对飞机模型气动特性的影响。结果表明，当来流减速时，升力系数增加，当来流加速时，升力系数减小；随着迎角的增大，非定常自由来流对升力系数的影响增大；当来流脉动频率一定时，随脉动幅值的增大，升力系数增大；当脉动幅值一定时，随脉动频率增大，升力系数增大。因此在研究飞机机动飞行的同时，考虑飞行速度变化的影响是十分必要的。

The effects of unsteady free stream on aerodynamics of an aircraft model

In this paper, the effects of unsteady free stream on aerodynamics of an aircraft model are studied in the unsteady wind tunnel of NUAA. The results contain the effects of angles of attack, different frequencies and amplitudes. The testing results show that with the angle of attack increasing the effects of unsteady free stream become very large and the unsteady aerodynamics are also increased with frequencies and amplitudes adding. These all are affected by the change of vortex breakdown positions and vortex intensity. Therefore, it is very necessary to study the effects of unsteady free stream on highly maneuverable aircraft.