通用直升机雷达散射特性及RCS减缩

采用物理光学法和等效电磁流法作为RCS(Radar Cross Section)数值计算方法,通过对某飞机模型的实验测试,验证了算法的有效性.建立了某通用直升机的几何外形模型,计算RCS特性并分析其重要散射源.进行机身外形和旋翼的RCS减缩研究,提出了通用直升机隐身外形设计方法.改形后全机雷达散射水平在头(尾)向和侧向分别降低至原型的10%和1%,且静稳定性及有效容积基本不变.通用直升机进行外形隐身设计后,旋翼成为全机的重要散射源(特别在头向及尾向),还须采用其他方法进行RCS减缩.

Radar scattering characteristics and RCS reduction of utility helicopter

The physical optics (PO) and the method of equivalent currents (MEC) were used as the numerical computation method, and its feasibility was verified by experiment. A geometric model of conventional utility helicopter was established. Then its radar cross section(RCS)was calculated and analyzed. RCS reduction research was done by modifying the geometric shape and changing the number of rotating blades. The low observable shape of utility helicopter was put forward without large variation in static stability and available volume. The average RCS of the modified utility helicopter in forward (backward) and side direction is equivalent to 10%, 1% of the conventional one respectively. Rotating blades become the main radar scattering source of the modified helicopter, especially in the forward and backward direction. Some other methods are need to reduce the RCS further.