关键词: 脉冲激光引信, 高速飞行, 光线追迹, 激波, 定距精度

Abstract: To improve the ranging accuracy of forward pulse laser fuzes on projectiles, it is necessary to study the impact of shock waves in front of the projectile under high-speed flight conditions. Based on the traditional pulse laser echo model, a semi-analytical method is proposed to model the pulse laser echo signals disturbed by shock waves, and the concept of the optimal confidence interval is introduced to construct the ranging data distribution and error evaluation model. This paper focuses on a typically shaped charge as the research object, employing a Reynolds average navier-stokes (RANS) solver for aerodynamic flow field calculations to obtain the density distribution around the projectile. Using Optical path difference (OPD) and Strehl ratio (SR) as criteria for evaluating aerodynamic optical effects, a high-precision fourth-order Runge-Kutta method is employed to trace the laser beam through the non-uniform flow field in front of the projectile. Simulation analysis was conducted to investigate the effects of different flight Mach numbers, target angles, and detection distances on the pulse laser echo waveforms and detection accuracy. The simulation results show that the ranging performance of pulse laser fuzes below 3 Mach is slightly affected, with the systematic error and random error reaching their minimum and maximum, respectively, at 4 Mach. This study provides theoretical foundations for suppressing the aerodynamic optical effects of pulse laser fuzes under high-speed flight conditions.

Key words: pulsed laser fuze, high-speed flight, ray tracing, shock wave, ranging accuracy