A method for calculating underwater explosion shock wave parameters of slender cone-shaped charges
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摘要: 为了计算锥形长药柱水下爆炸冲击波压力,以及研究长脉宽冲击波的传输特性,基于叠加原理建立了冲击波压力-时间曲线的计算方法,通过实验验证了该方法的有效性,在此基础上分析了锥形长药柱不同方位冲击波压力的分布规律。研究结果表明:锥形长药柱产生的冲击波压力具有各向异性,在起爆端一侧形成的是具有厚波头特征的低幅值长脉宽冲击波,在装药径向形成的是接近指数衰减的高幅值冲击波,而在远离起爆端的冲击波压力幅值和脉宽则介于前两者之间。锥形长药柱与球形装药冲击波分布的差异是由于装药形状和起爆方式的改变所导致的,由于装药不同部位起爆的时间差,导致水下爆炸冲击波在不同位置的叠加效果存在明显差异,药柱周围流场中形成的冲击波压力具有方向性。利用提出的计算方法得到的计算结果与实验结果和数值模拟结果吻合较好,研究结果可为锥形长药柱水下爆炸冲击波威力场和毁伤评估提供参考和依据。Abstract: In order to estimate the underwater explosion shock wave pressure of slender cone-shaped charges and to study the characteristic of long duration shock waves, an engineering model based on the superposition principle was proposed. Cone-shaped charges are usually used to simulate the far-field shock wave of large equivalent explosives, and the wave strength is generally on the order of MPa, which can be regarded as a weak shock wave, so the problem can be simplified based on the acoustic approximation assumption. Based on the above analysis, the cone-shaped charge is divided into several small charges, and then the shock wave pressure generated by each small charge in the water is superimposed according to the propagation order of the detonation wave to obtain the shock wave pressure curve of the whole cone-shaped charge. The validity of the model was verified through experimental results. Then, the transmission characteristics and the pressure profile of the shock wave at different azimuths of the cone-shaped charge were analyzed. The results show that the shock wave is anisotropic around the charge. Long duration, low amplitude shock waves with a thick wave head are generated at the detonation end. Exponential decaying shock waves with high amplitude are formed on the side of the charge, while on the opposed side of the detonation end the amplitude and duration of the shock wave are between the former two. The differences in the shock wave distributions between the cone-shaped and spherical charges are related to their shapes and detonation methods. Due to the differences in the explosion initiation times of different parts of the explosive charge, the superimposition effect of shock waves at different azimuths is obviously different, which result in an anisotropic pressure field. The proposed method is in good agreement with the experimental and numerical simulation results, which can provide reference and basis for the power and damage assessment of the underwater explosion shock wave of the cone-shaped charges.s of cone-shaped charges.
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Key words:
- underwater explosion /
- shock wave /
- cone-shaped charge /
- long duration pressure
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表 1 锥形长药柱几何参数
Table 1. Geometric parameters for the slender cone-shaped charges
装药结构 l1/mm l2/mm d1/mm d2/mm d3/mm W/kg 单锥长药柱 2 000 35.9 71.8 7.5 双锥长药柱 300 1200 27.5 55.0 82.5 7.8 表 2 锥形长药柱材料参数
Table 2. Material parameters for the slender cone-shaped charges
装药类型 ρ/(kg·m−3) D/(km·s−1) c/(km·s−1) α1 α2 TNT 1 580 6.9 1.5 1.18 −0.185 -
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