利用CFD技术计算飞行器动导数

利用非定常流场数值计算方法模拟飞行器强迫俯仰振荡仅能得到俯仰力矩系数对迎角变化率和俯仰角速度的动导数之和,而动稳定性分析需要单独的动导数数值.为解决这个问题,利用滑移网格模拟强迫振荡运动,得到俯仰力矩系数对迎角变化率和俯仰角速度的动导数之和.利用旋转参考坐标系模拟定常拉升,得到俯仰力矩系数对俯仰角速度的动导数.利用旋转参考坐标系模拟匀速滚转,得到滚转力矩系数对滚转角速度的动导数.对有翼导弹和水上飞机进行了纵向和横向动导数的计算.计算结果与试验数据、文献数据以及其他方法得到的结果具有较好的一致性,表明提出的方法可用于复杂外形飞行器动导数计算.

Aircraft dynamic derivatives calculation using CFD techniques

Only the sum of aircraft pitching moment angle of attack(AOA) rate derivative and pitch rate derivative could be obtained by simulating the forced pitch oscillation using the unsteady flow numerical calculation method. But the dynamic stability analysis needs separate dynamic derivatives. To solve this problem, the sliding mesh was applied to simulate the forced pitch oscillation, and the sum of pitching moment AOA rate derivative and pitch rate derivative was obtained. Then the rotating reference frame was used to gain the pitching moment pitch rate derivative by simulating the steady climb movement. The rotating reference frame was also employed to acquire the rolling moment roll rate derivative by simulating the steady roll movement. The dynamic derivatives of a missile with cruciform tails and a seaplane were calculated. The results were consistent with experimental data, reference data and results acquired using other methods, indicating that this method could be used to calculate the dynamic derivatives of aircrafts with complicated configurations.