Modeling and analysis of water discharge trajectory with large capacity monitor

• 3D simulation model of the straight water discharge using MPS was constructed.
• Detailed characteristics of water discharge trajectory were confirmed.
• Flying behavior of water correlate with the discharge condition was made clear.
• New model which can predict simply the water discharge trajectory was presented.
• Optimal discharge conditions for fighting fuel oil tank fires can be proposed.

In the event that a full-blown fire occurs in a large fuel oil storage tank of over 34 to 100 m in diameter and of over 10 to 20 m in height, the firefighting will be carried out using a set of large capacity monitors. It is important to estimate the discharge trajectory of water and/or fire-foam in order to avoid the thermal updrafts from the burning oil surface, and utilizing the entrainment around the peripheral zone of a tank edge. A large-scale water discharge with flow of 10 to 40 kL/min, pressure of 0.6 to 0.9 MPa was simulated using a 3D simulation model based on the Moving Particle Semi-implicit (MPS) method, and it was confirmed that the flying behavior and the water discharge trajectory correlates with the discharge flow and pressure. The water discharge which was described using this 3D simulation model gave good agreement with the recommended curved lines from the Disaster Management Committee. It is suggested that this model can estimate with precision the percentage of the delivered water mass into a tank, and can be a useful support tool for fighting tank fires.