Numerical analyses of the RCS characteristics of a vehicle body with concave/convex surface features

Abstract

The influence of minor geometrical features on vehicle surfaces on the radar stealth characteristics was analyzed in simulations. Numerical analyses of the electromagnetic scattering characteristics were conducted using a simplified vehicle side door with minor seams, grooves and convex geometrical features (bullet-proof glass and a metal bar for a door-seal). The results show that these minor uneven surface features negatively affect the body's radar cross section (RCS) characteristics. The numbers of incidence angles for the RCS area greater than 10 dBsm for the simplified vehicle side doors with minor seams and grooves are up to 2.2 and 2.8 times that of a smooth metal plate. The number of incidence angles for the RCS area greater than 10 dBsm for an armored vehicle side door with bullet-proof glass is 5.4 times greater while that with a metal bar seal is 1.7 times greater. Electromagnetic scattering experiments using a rectangular aluminum plate with a rectangular aluminum bar frame on one side show that the bar frame increases the plate's RCS area. Thus, even minor uneven surface features on a vehicle body increase the numbers of incidence angles for the RCS area greater than 10 dBsm, although they have less influences on the maximum peak RCS area. Therefore, exterior surface seams, grooves and convex features should be avoided to improve the radar stealth characteristics.

Abstract

摘要 特种地面车辆防雷达侦察的隐身性能研究需关注车身表面不平整特征的影响。该文对具有表面缝隙和凹槽结构的简化车身侧部结构、具有表面突出特征 (透明装甲结构、密封钢带结构) 的简化车身侧部结构的雷达散射截面 (RCS) 面积分布特性进行了仿真分析, 量化描述了表面局部非平整特征对结构整体的RCS面积分布特性的不利影响。与金属平板结构相比, 具有表面缝隙或凹槽结构的简化车身侧部结构的RCS面积大于10 dBsm的入射方位数分别增加到2.2倍、2.8倍; 表面有透明装甲或密封钢带凸特征的两种车身侧部结构的RCS面积大于10 dBsm的入射方位数分别增加到5.4倍、1.7倍。对表面有、无圆柱铝条的金属平板结构的实验测试结果验证了局部非平整特征对结构整体的RCS面积的增强效应, 也验证了RCS面积分布特性计算分析方法的准确性。金属表面的非平整结构可显著增加RCS面积大于10 dBsm的入射方位数, 而对结构整体的RCS面积最大值的影响较小。在隐身车身设计时, 应减小车门缝隙、内凹与外凸类非平整结构的尺度、数量, 尽可能保持车身外表面平整。