The mitigation of blast shock with water has broad application prospects. Understanding the mitigation effects on the reflected overpressure of the explosion shock with water surrounding an explosive in a confined space is of great significance for military explosives safety applications. To estimate the effects of the parameters on the reflected overpressure of blasted shock wave, a series of experiments were carried out in confined containers with spherical explosives immersed in a certain thickness of water, and numerical simulations were conducted to explore the corresponding mechanisms. The results reveal that the reflected overpressure is abnormally aggravated at a small scaled distance. This aggravation is due to the high impulse of the bulk accelerated water shell converted from the explosion. With increasing scaled distance, the energy will be gradually dissipated. The mitigation effects will appear with the dispersed water phase front impacting at a larger scaled distance, except in the case of a dense water phase state. A critical scaled distance range of 0.7–0.8 m/kg^1/3 for effective mitigation was found. It is suggested that the scaled distance of space walls should be larger than the critical value for a certain water-to-explosive weight ratio range (5–20).

用水减轻爆炸冲击具有广阔的应用前景。了解密闭空间中爆炸物周围的水对爆炸冲击的反射超压的缓解作用，对军事爆炸物安全应用具有重要意义。为了评估参数对冲击波反射超压的影响，在密闭容器中将球形炸药浸入一定厚度的水中进行了一系列实验，并进行了数值模拟，以探讨相应的机理。结果表明，反射的超压在较小的比例距离上会异常加重。这种加剧的原因是爆炸产生的大量加速水壳受到了强烈的冲动。随着缩放距离的增加，能量将逐渐消散。除非在浓水相状态下，否则分散的水相前部会在更大的比例距离上发生冲击，从而产生缓解效果。临界刻度距离范围为0.7–0.8 m / kg发现有^1/3的有效缓解措施。建议在一定的水炸重量比范围（5-20​​）下，间隔壁的标定距离应大于临界值。