飞机大振幅滚转运动动态气动特性实验研究

在南航NH-2低速风洞中,对BJ-1飞机模型动态气动特性进行了实验研究.模型在不同攻角、不同振幅和不同频率时绕体轴作大振幅滚转运动,测量了模型的动态气动特性,着重分析了模型不同运动参数对模型滚转力矩和偏航力矩的影响.结果表明,模型攻角从小到大变化过程中,模型的滚转阻尼和偏航阻尼变化很大,滚转力矩和偏航力矩迟滞环变化方向发生改变.模型滚转频率对模型的滚转阻尼和偏航阻尼影响不明显,只改变力矩迟滞环的大小.随着模型振幅增加,滚转力矩和偏航力矩迟滞环从一个变成3个,出现2个交叉点,大滚转角时滚转阻尼和偏航阻尼特性与小滚转角时的相反.

Investigation of the unsteady aerodynamic characteristics for a fighter rolling in large amplitude

The test was conducted in the low speed wind tunnel of NH-2 in Nanjing University of Aeronautics and Astronautics. The test model was BJ-1 fighter model. The six-component unsteady aerodynamic was measured during the model rolling in large amplitude around the body-axis at different angles of attack,different roll amplitude or different roll oscillating frequencies. The unsteady roll moment and yaw moment of the model were analyzed. The results show that the damping characteristic of the roll moment and the yaw moment can be greatly changed at different angles of attack. But the change of oscillating frequency effects the damping characteristic of the roll moment and the yaw moment on the magnitude only. When the amplitude of roll is increased, the moment loops of the hysteresis appear 2 points of intersection and damping characteristic of the roll moment and the yaw moment at the range of small amplitude oscillating is opposite to that of at the range of large amplitude oscillating.