一种水下爆炸冲击波压力调控方法

起爆位置和装药形状对水下爆炸冲击波压力有较为显著的影响，这使得利用小当量装药在局部方向形成与大当量装药一定程度等效的冲击波成为可能。为了能够在小当量装药条件下开展舰船结构及设备抗水下爆炸冲击实验，基于细长装药结构和参数优化设计，设计了一种冲击波压力幅值和持续时间可调的装药方法。首先，基于简单波理论给出了水下爆炸冲击波压力调控的原理，以及装药参数优化设计的目标函数和约束条件；然后，采用自主数值模拟软件研究了细长装药的水下爆炸能量输出规律，通过实验验证了数值模拟的置信度，研究发现起爆位置和装药形状对水下爆炸冲击波压力峰值和持续时间的影响是显著的，在炸药爆速一定的情况下，长药柱水下爆炸冲击波压力的持续时间可通过几何近似确定；最后，为了进一步考察该方法的有效性，以1000 kg TNT和100 m爆距的水下爆炸冲击波压力-时间曲线作为原型，设计了2种与该原型冲击波压力等效的装药方案，并通过数值模拟进行了验证。研究结果表明:设计的装药能够在预定的持续时间内，在装药起爆端一侧形成与原型等效的冲击波压力-时间曲线。由于没有考虑对气泡载荷的等效，因此该调控方法仅适用于中远场爆炸冲击问题。

A method for adjusting and controlling underwater explosion shock wave

The detonation position and the shape of the explosive have a significant influence on the pressure of the underwater explosion shock wave, which makes it possible to use a small charge to form a shock wave that is equivalent to a large charge in a local direction. A charge design method to adjust the amplitude and duration of shock wave pressure was established based on the slender charge structure and parameter optimization design to carry out an underwater explosion shock resistance test of ship structure or equipment using a small charge. Firstly, based on the simple wave theory, the principle of shock wave pressure control and the objective function and constraint conditions of optimal design of charge parameters are given. Then, an independently developed software is used to study the energy of underwater explosion of slender charge, and the confidence degree of numerical simulation is verified through experiments. It is found that the influence of initiation position and charge shape on the pressure peak and duration of the underwater explosion shock wave is significant. The duration of shock wave pressure of slender charge column underwater explosion can be determined by geometric approximation. Finally, to further investigate the effectiveness of the proposed method, two charge schemes equivalent to the shock wave pressure of the prototype were designed and verified by numerical simulation. The prototype is taken from the pressure-time curve of the underwater explosion shock wave with TNT equivalent to 1000 kg and a stand-off of 100 m. The comparison results show that the designed charge can form a shock wave pressure-time curve equivalent to that of the prototype on the side of the initiation end within a predetermined duration. Since the bubble pulse is not considered, the established method applies only to the middle and far-field explosion shock problem.