Abstract: The mitigation effect of water on blast shock is investigated. The explosion is tested in a confined space without and with water in order to estimate the influences of the parameters, such as water-to-explosive weight ratio and scaled distance, on the reflected overpressure of shock wave. The results indicate that the reflected overpressure of explosion immersed in water firstly increases and then decreases with the increase in scaled distance compared with that without water. It is found that the reflected overpressure significantly increases with the increase in the water-to-explosive weight ratio when the scaled distance is not larger than 0.255 m/kg¹³. Typically, the overpressure increases eight-fold when the ratio is 6. The overpressure can be decreased by 60% by using water when the scaled distance is 1.21 m/kg¹³.

Key words: explosion mechanics, water mitigation effect, shock wave, water-to-explosive weight ratio, explosion vessel