Experimental analysis of the explosion mechanism of gasoline vapor in a small leisure boat

摘要

The mechanism that produces an explosion from the vapor of gasoline in a small leisure boat is elucidated by using a small-scale combustion chamber and a mock-up boat. The study reveals that the explosion is caused by: (i) leakage of gasoline vapor from a fuel tank, (ii) diffusion and accumulation of gasoline vapor in a battery compartment, and (iii) ignition of premixed gas and flame propagation between linked compartments. The leakage of gasoline vapor from the fuel tank is successfully visualized by the schlieren method. The process of diffusion of the gasoline vapor from the fuel-tank compartment to the battery compartment is demonstrated in the mock-up boat. A flammable mixture of gasoline vapor in the battery compartment has been estimated to be maintained from the 1.7th day to the 175th day after placement of the filled and leaking fuel tank. Ignition of the premixed gas and the flame propagation process are verified by using the small-scale combustion chamber. A high-speed camera visualizes the behaviors of ignition and flame propagation during the course of explosions in linked compartments. Finally, in order to confirm the presumed mechanism, a reproducibility test is carried out by using the mock-up boat to simulate the situation in the actual accident. The actual explosion is successfully reproduced in the mock-up boat.