Research on water jet rescue system: [Assessment and improvement of its safe distances]

In order to study the safe distance for human beings in the applications of water jet, this paper studied effects of water jets impacting on the surfaces of pigskins. Cutting experiments with water jet and abrasive water jet were carried out by using pigskins instead of humanʹs skins. The experimental results showed that the most dangerous standoff distance is 35∼46cm or less and the safe distance is over 115cm for a single water jet; the most dangerous standoff distance is within 62cm and the safe distance is over 154cm for a single abrasive water jet; the most dangerous standoff distance is 5∼9cm with the collision angle of 60°, while it is 8∼15cm with the collision angle of 30°, and the safe distance is over 51cm for two collided abrasive water jets.