射线追踪法在球面收敛调节片喷管RCS计算中的应用

Application of ray-tracing method in calculating RCS for spherical convergent flap nozzle

结合射线追踪法的原理,利用自主开发的电磁散射特性计算程序,对具有不同尾缘修型的球面收敛调节片喷管进行了数值模拟计算,分别得到了不同喷管内部腔体散射场和喷管出口边缘绕射场的雷达散射截面积(RCS),并且通过计算获得了不同入射方位角上喷管腔体内壁面上的感应电流,通过对感应电流的分析,从本质上解释了RCS的变化规律.研究结果表明:对喷管出口尾缘所采用的修型措施在降低喷管出口边缘绕射场的RCS和改善喷管电磁隐身性能方面效果显著;相对于普通的遮挡算法,射线追踪法将计算周期缩短了21%以上,明显地提高了计算效率;利用感应电流的分析方法能够清晰直观地从本质上解释RCS的变化规律,并且具有较高的可靠性.

Numerical simulation of spherical convergent flap nozzles with different trailing edges shaping measures was finished using the self-developed electromagnetic scattering characteristic program based on the ray-tracing method.Radar cross section（RCS）of inner cavity scattering field and edge diffraction field was obtained for above several different SCFN.Meanwhile,induced electric current of inner cavity wall at different azimuth angles was calculated.With the method of analyzing the induced electric current,the change law of RCS was explained essentially.The analysis results show that the shaping measures for the trailing edge of the nozzle have a significant and obvious effect on decreasing the RCS of edge diffraction field and improving the electromagnetic stealth performance.Compared with ordinary occultation algorithm,the ray-tracing method shortens computational cycle by 21%,and improves the computing efficiency obviously.The analysis method using induced electric current can explain the change law of RCS clearly and intuitively with a high reliability.