机头颗粒微扰动对战斗机大迎角航向气动特性的影响研究(英文)

Study on the impact of particle perturbation on yaw characteristics of aircraft at high angles of attack

本文重点介绍了在机头周向角±45°处的颗粒微扰动对战斗机大迎角航向气动特性的影响进行了数值模拟研究。结果表明:在机头周向角±45°处的颗粒对大迎角下飞机的航向气动特性影响明显,能够使大迎角偏航力矩具有确定的方向。对流场结构分析发现:颗粒所在一侧脱离出明显强于没有颗粒一侧的小涡,从而在机头该侧诱导出更强的分离涡,进而导致了飞机大迎角非对称气动力的出现。

The numerical study of the impact of small-particle-perturbation on the nose tip where the circumferential angle is ±45°on yaw characteristics of aircraft at high angles of attack is introduced.The results demonstrate that the small-particle at the circumferential angle of ±45° has great impact on the yaw characteristics,and it helps to fix the direction of the side force and yawing moment.On basis of the flow vortices structure observation,it is shown that the vortex sheds from the side of small-particle is stronger than the other one on the opposite side,and this vortex induces a stronger separation bubble on the lateral side of the forward fuselage,which lead to large side force at high angle of attack.