Abstract: Combining iterative physical optic approach (IPO) with equivalent edge currents method (EEC)，a code which could calculate the edge diffraction field and scattering field of the cavity was built to simulate the radar scattering characteristics of two-dimensional (2-D) nozzles. In order to improve the computational efficiency，OpenMP and MPI parallel technologies were adopted. On this basis，the electromagnetic scattering characteristics of different aspect ratio 2-D nozzles under horizontal polarization and vertical polarization were analyzed，and the Radar cross section ( RCS ) curves of the total field and edge diffraction field of 2-D nozzles under the different detection angles were obtained. The calculation results show that aspect ratio can affect the total field and edge diffraction field under the two polarization ways. But it has a greater impact on the former. In the calculation results，2-D nozzle with the aspect ratio of 2 has lower RCS values than the others under the two polarization ways. Comparing with the model with the aspect ratio of 1.5，the value of RCS could be reduced by 4.98% and 6.72%，respectively，which is under horizontal polarization and vertical polarization.

Key words: Nozzle；Aspect ratio；Iterative physical optic approach；Radar cross section；Parallel computation

摘要： 为研究宽高比对二元喷管雷达散射截面( RCS )的影响，结合迭代物理光学法和等效边缘电磁流法开发了腔体电磁散射特性计算程序，用来分析二元喷管的雷达散射特性；并采用OpenMP和MPI两种并行技术提高计算效率。对比分析了不同宽高比( AR )的二元喷管在水平极化及垂直极化方式下的电磁散射特性，并给出了二元喷管在不同探测角下总散射场与边缘绕射场的 RCS 曲线。研究结果表明，在两种极化方式下，宽高比对边缘绕射场的 RCS 值影响不大而对总散射场影响较大；宽高比为2.0的模型在两种极化方式下，都具有较低的 RCS 值，相比宽高比为1.5的模型在水平极化方式和垂直极化方式下分别减少4.98%和6.72%。

关键词: 喷管；宽高比；迭代物理光学法；雷达散射截面；并行计算