外形修形对球面收敛矢量喷管RCS的影响

航空发动机是飞行器后向电磁散射的主要贡献源，对其采用雷达散射截面积缩减措施能够有效地提升飞行器后向隐身性能。球面收敛矢量喷管能够满足新一代战斗机对于机动性和隐身性的综合需求。基于迭代物理光学法，研究了对喷管扩张段进行不同角度斜切、修齿后球面收敛矢量喷管的后向雷达散射截面积分布。研究结果表明：斜切在俯仰平面上的RCS缩减能力较强，斜切角度为30°具有最佳的RCS缩减效果；修齿修形能够在两个探测面均体现较好的RCS缩减能力，发动机出口齿角为100°时具有最佳的RCS缩减效果；对航空发动机进行外形修形需要在飞机设计阶段进行综合考虑。

Influence of Shape Modification on RCS of Spherical Convergent Flap Nozzle

The aero engine is a main contribution to the backward electromagnetic scattering of the aircraft, and the radar cross section(RCS) reduction measures adopted enable to effectively improve the aircraft stealth performance. The spherical convergent flap nozzle (SCFN)can meet the comprehensive needs of new generation fighters for maneuverability and stealth. The iterative physical optics method is used to calculate the backward RCS of the spherical convergence vector nozzle under different angles of beveling and tooth modification. The results show that the beveling modification has a better RCS reduction ability at the pitch plane. When the beveling is at an angle of 30°, the reduction ability is better than that of the other beveling angle. The tooth modification has RCS reduction ability at the both plane. When the tooth angle is at an angle of 100°, the reduction ability is better than that of the other tooth angle. The shape modification of aero engines requires comprehensive consideration in the aircraft design stage.