关键词: 高超声速滑翔飞行器, CFD, 雷达散射截面, 锐边化, 倒圆角

Abstract:

Stealth performance is one of the key indicators affecting the combat effectiveness of hypersonic weapons. To improve the survivability and penetration capability of hypersonic glide vehicles， the HTV-2 aircraft is used as the initial shape， and the design idea of sharp edges is introduced to propose an aerodynamic shape with good stealth performance. Firstly， CFD numerical simulation and the high-frequency approximation algorithm are used to evaluate the aerodynamic characteristics and stealth characteristics of the initial shape. Then， a sharp-edged aircraft shape is designed by intercepting important cross-sectional contour lines， uniformly selecting control points and reconstructing the three-dimensional shape. On this basis， the lift-drag characteristics and the Radar Cross Section （RCS） of the sharpened configuration are calculated and evaluated. Compared with the original shape， the aerodynamic performance of the sharpened shape changes slightly， with the change in the aerodynamic coefficient within 7%. Meanwhile， in the main threat area， where the pitch angle and the yaw angle vary within ±30° and ±60°， respectively， the average RCS of the aircraft is significantly reduced， with an average drop of more than 20%. In addition， to eliminate the influence of edge diffraction， the edge of the sharpened shape is rounded， further reducing the average RCS value in the main threat area by more than 60%. The effects of rounded corners at different positions and the radius of the corners on the stealth characteristics of the aircraft are further studied. The results show that the rounding of the tail section can considerably improve the stealth characteristics of the aircraft， particularly when the ratio of the radius of the rounded corner to the characteristic length of the aircraft is 1.35%.

Key words: hypersonic glide vehicle, CFD, radar cross section, sharpening, rounding