雷达隐身措施对Caret进气道性能影响的数值计算

Numerical Calculation of the Influence of Radar Stealth Measures on Caret Inlet Performance

中文关键词:  Caret进气道  转子叶片  S弯扩压段  低散射材料  吸波导流板  雷达散射截面  航空发动机

英文关键词:Caret inlet  rotor blade  S-shaped diffuser  low-scattering material  baffle board  radar cross section  aeroengine

中文摘要:

      针对S弯Caret进气道气动与电磁散射特性研究，采用多层快速多极子（MLFMM）数值计算方法，对比分析了转子叶片转 动相位角变化对进气道雷达散射截面（RCS）的影响。采用剪切应力输运（SST） k-ω湍流模型求解N-S方程，计算黏性流场并分析 进气道气动性能，对比分析了扩压段的构型和吸波导流板的安装方式对进气道气动与雷达隐身性能的影响。结果表明：转子叶片 相位角的变化会导致进气道RCS在同一雷达波入射角度下出现变动，但不会改变RCS随雷达波入射角度的变化规律；采用双S弯 扩压段可以有效降低进气道出口畸变和提升Caret进气道的雷达隐身性能，使其在2种工况下平均RCS均小于-2 dB，由叶片旋转 导致的RCS最大差值均小于-3.5 dB，但也会导致进气道临界压力的降低；安装合适的吸波导流板可以有效提升进气道的雷达隐 身性能，但会造成进气道出口畸变的增加。

英文摘要:

      In order to study the aerodynamic and electromagnetic scattering characteristics of an S-shaped Caret inlet, the influence of the phase angle of the rotor blade on the radar cross section (RCS) of the inlet was analyzed by using multi-layer fast multipole (MLFMM) numerical calculation method. The shear stress transport (SST) k-ω turbulence model was used to solve N-S equations, calculate the viscous flow field, and analyze the aerodynamic performance of the inlet. The influences of diffuser configurations and baffle board installa? tion modes on the aerodynamic and radar stealth performance of the inlet were analyzed and compared. The results show that the change of rotor blade phase angle will lead to the RCS change of the inlet at the same radar wave incidence angle, but it will not change the variation laws of RCS with incidence angle. The use of a double S-shaped diffuser can effectively reduce the outlet distortion and improve the radar stealth performance of the Caret inlet, making the average RCS less than -2dB under two working conditions, and the maximum difference of RCS caused by blade rotation less than -3.5dB, but it will also lead to the decrease of the critical pressure of the inlet. The installing of a suitable baffle board can effectively improve radar stealth performance of the inlet, but will lead to the increase of outlet distortion of the inlet duct.