外调节片对轴对称喷管电磁散射特性影响研究

Electromagnetic Scattering Characteristics of Outer Flaps to Axisymmetric Nozzle

关键词:  外调节片  轴对称可调喷管  电磁散射  迭代物理光学法  雷达散射截面积

Key words:  Outer flaps  Axisymmetric variable-area nozzle  Electromagnetic scatter  Iterative physical optics  Radar cross section

摘要:

为研究外调节片与出口面积可调喷管外壁面无法完全闭合时形成的腔体结构对喷管后向电磁散射特性的影响，针对某型轴对称出口面积可调喷管简化模型，在三种电磁波探测频率下，采用迭代物理光学法分别对带外调节片和不带外调节片喷管的雷达散射截面积（Radar cross section，RCS）进行了数值模拟分析，得到外调节片腔体对喷管电磁散射特性的影响规律。研究结果表明，外腔体使得喷管0°探测角处的雷达散射截面积明显增大；中心锥端面和气流进口平面是喷管内腔体的强电磁散射源，外腔体未出现强散射源；外腔体对喷管雷达散射截面积的影响与探测频率没有明显相关性。

Abstract:

To study the effects of the cavity structure formed by outer flaps and outer wall surface of the nozzle with adjustable outlet area on the backward electromagnetic scattering characteristics of the nozzle， aiming at the simplified model of a certain axisymmetric nozzle with adjustable exit area， the radar cross section（RCS） of nozzle with and without outer flaps under three incident frequencies were obtained by using the numerical method-iterative physical optics（IPO） to study the effects of outer cavity on the backward electromagnetic scattering characteristics of the nozzle. The results show that the outer cavity increases the RCS at 0°detection angle of the nozzle significantly. The end surface of the central cone and the air inlet plane are strong electromagnetic scattering sources in the inner nozzle， and there is no strong scattering source in the outer cavity. At the same time， the effect of the outer cavity on the RCS of the nozzle has no obvious correlation with incident frequency.